Silicon-based Solar Cells Research Articles

Improving open-circuit voltage and short-circuit current of high-efficiency silicon-based planar heterojunction solar cells by combining V2O5 with PEDOT:PSS

In recent years, a novel PEDOT:PSS/n-Si planar heterojunction solar cell has been extensively studied in the photovoltaic field. Different V2O5-IPA concentrations mixed in PEDOT:PSS samples as hole transport layer were prepared by means of spin coating technique and mechanical mixing of organic and inorganic materials. V2O5 was studied for its effects on the surface morphology, chemical composition, and optical transmittance of PEDOT:PSS films. The findings of the study show that the addition of V2O5 particles changes the surface morphology of PEDOT:PSS films and promotes its superior ohmic contact with the Si interface. Furthermore, PEDOT:PSS incorporated with V2O5 particles that have outstanding optical and semiconductor properties reduces the rate of carrier recombination at the device interface and blocks electron transport to the anode in the fabricated Si-based solar cells. When compared to conventional PEDOT:PSS/Si planar heterojunction solar cells, the fill factor, photoelectric conversion efficiency, open-circuit voltage, and short-circuit current density of the devices prepared in this study can be significantly improved, reaching up to 70.98%, 15.17%, 652 mV and 32.8 mA/cm2, respectively. This research provides a promising and effective method for improving the photoelectric conversion performance of PEDOT:PSS/Si heterojunction solar cells, which enables the application of V2O5 in Si solar cells.

Halide Composition Engineered a Non-Toxic Perovskite–Silicon Tandem Solar Cell with 30.7% Conversion Efficiency

Since the conversion efficiency of silicon (Si)-based solar cells stagnates at 26.7% in the literature, extensive research and development activities are carried out on perovskite silicon-based tandem solar cells. However, the presence of lead (Pb) and the instability of perovskite prevent their large-scale implementation in the photovoltaic industry. Therefore, it is important to replace the hazardous material (Pb) in perovskite top cells to design non-toxic perovskite–silicon tandem solar cells. The current work yields much-needed studies to develop a non-toxic perovskite–silicon-based tandem solar cell. For the first time, methylammonium tin mixed halide (MASnI3–xBrx)-based materials are comprehensively investigated and optimized with respect to different halide compositions, absorber layer thickness, and bulk defect density in standalone configurations, followed by the development of a lead-free MASnI2Br1–Si-based tandem solar cell. The transfer matrix method and current matching techniques are used to design the two-terminal monolithic tandem cell, which showed a maximum conversion efficiency of 30.7% with an open circuit voltage (VOC) of 2.14 V. The results outlined in this manuscript will pave the way for the progress of highly efficient, non-toxic perovskite–silicon tandem solar cells.

Facial synthesis of p-p heterojunction composites: Evaluation of their electrochemical properties with photovoltaics-electrolyzer water splitting using two-electrode system

Mixed transition metal oxides have garnered widespread interest as alternative electrocatalysts for the oxygen and hydrogen generation reactions; however, they tend to require extended synthetic routes, in addition to possessing limited electrocatalytic activities and stabilities. Herein, we report the observation of a synergistic effect between the non-precious metal oxides Mn3O4 and Co3O4 with CuO and NiO, wherein the resulting composites exhibit promising properties as catalysts for the alkaline water electrolysis process. The activities of these composites in both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) were improved compared to their counterparts, and the dynamic potentials of these processes were reduced. Importantly, low overpotentials of 202 and 380 mV were found for the CuO–Mn3O4 composite catalysts for the OER and the HER at 10 mA/cm2, respectively. In addition, electrochemical impedance spectroscopy measurements showed a reduced impedance response for the composites, which was dominated by the relaxation of the intermediate frequency associated with the adsorption of the intermediate. Furthermore, the superior catalytic activities of the composites were attributed to their structural properties, high electroactive surface areas, fast electron transport kinetics, and good chemo-electrical bonding between Mn3O4 and CuO. Importantly, merging with a marketable silicon-based solar cells, the accumulated PV-EC water splitting device obtains greater hydrogen production under stimulated solar light irradiation. This work offers a typical demonstration and respected strategies for practical large-scale solar H2 production via an economical PV-EC technology.

Recent advances in carbon-based materials for high-performance perovskite solar cells: gaps, challenges and fulfillment.

Presently, carbon-based nanomaterials have shown tremendous potential for energy conversion applications. Especially, carbon-based materials have emerged as excellent candidates for the fabrication of halide perovskite-based solar cells, which may lead to their commercialization. In the last decade, PSCs have rapidly developed, and these hybrid devices demonstrate a comparable performance to silicon-based solar cells in terms of power conversion efficiency (PCE). However, PSCs lag behind silicon-based solar cells due to their poor stability and durability. Generally, noble metals such gold and silver are employed as back electrode materials during the fabrication of PSCs. However, the use of these expensive rare metals is associated with some issues, urgently necessitating the search for cost-effective materials, which can realize the commercial applications of PSCs due to their interesting properties. Thus, the present review shows how carbon-based materials can become the main candidates for the development of highly efficient and stable PSCs. Carbon-based materials such as carbon black, graphite, graphene nanosheets (2D/3D), carbon nanotubes (CNTs), carbon dots, graphene quantum dots (GQDs) and carbon nanosheets show potential for the laboratory and large-scale fabrication of solar cells and modules. Carbon-based PSCs can achieve efficient and long-term stability for both rigid and flexible substrates because of their high conductivity and excellent hydrophobicity, thus showing good results in comparison to metal electrode-based PSCs. Thus, the present review also demonstrates and discusses the latest state-of-the-art and recent advances for carbon-based PSCs. Furthermore, we present perspectives on the cost-effective synthesis of carbon-based materials for the broader view of the future sustainability of carbon-based PSCs.

Analyzing the ZnO and CH3NH3PbI3 as Emitter Layer for Silicon Based Heterojunction Solar Cells

Today, it has become an important task to modify existing traditional silicon-based solar cell factory to produce high-efficiency silicon-based heterojunction solar cells, at a lower cost. Therefore, the aim of this paper is to analyze CH3NH3PbI3 and ZnO materials as an emitter layer for p-type silicon wafer-based heterojunction solar cells. CH3NH3PbI3 and ZnO can be synthesized using the cheap Sol-Gel method and can form n-type semiconductor. We propose to combine these two materials since CH3NH3PbI3 is a great light absorber and ZnO has an optimal complex refractive index which can be used as antireflection material. The photoelectric parameters of n-CH3NH3PbI3/p-Si, n-ZnO/p-Si, and n-Si/p-Si solar cells have been studied in the range of 20–200 nm of emitter layer thickness. It has been found that the short circuit current for CH3NH3PbI3/p-Si and n-ZnO/p-Si solar cells is almost the same when the emitter layer thickness is in the range of 20–100 nm. Additionally, when the emitter layer thickness is greater than 100 nm, the short circuit current of CH3NH3PbI3/p-Si exceeds that of n-ZnO/p-Si. The optimal emitter layer thickness for n-CH3NH3PbI3/p-Si and n-ZnO/p-Si was found equal to 80 nm. Using this value, the short-circuit current and the fill factor were estimated around 18.27 mA/cm2 and 0.77 for n-CH3NH3PbI3/p-Si and 18.06 mA/cm2 and 0.73 for n-ZnO/p-Si. Results show that the efficiency of n-CH3NH3PbI3/p-Si and n-ZnO/p-Si solar cells with an emitter layer thickness of 80 nm are 1.314 and 1.298 times greater than efficiency of traditional n-Si/p-Si for the same sizes. These findings will help perovskites materials to be more appealing in the PV industry and accelerate their development to become a viable alternative in the renewable energy sector.

Four-terminal perovskite/silicon series solar cells with 28% efficiency achieved by suppressing edge recombination

Although the commercial application of solar cells pursues scalable and large-area devices, small-area solar cells on a scale of several centimeters possess many advantages such as low fabrication cost and facile high-throughput screening in the research laboratory. Most emerging photovoltaic technology starts from the studying of small-area devices. Recently, perovskite/silicon tandem solar cells have aroused extensive research interest because they can break through the radiative efficiency limit of single-junction solar cells. However, when commercial large-area silicon cells are cut into small pieces with a few squared centimeters in area for laboratory use, there occurs a significant efficiency loss, limiting the performance of tandem cells. Herein, to eliminate the thermal damage caused by the traditional laser cutting method and also reduce the non-radiative recombination of heterojunction silicon cells after being cut, a cold-manufacturing method of grinding wheel dicing is used to cut heterojunction silicon cells. This method is realized by high-speed mechanical grinding accompanied by liquid washing, which avoids damaging the edge of solar cell caused by heat. Compared with the device cut by laser, the heterojunction silicon cells cut by the cold-manufacturing method exhibit less cross-sectional damage. The measurements by scanning electron microscopy (SEM) and three-dimensional optical profilometer reveal that the morphology of the device edge is smoother than the counterpart cut by laser. Device physics measurements including electrochemical impedance spectrum(EIS), dark current-voltage curves, transient photovoltage (TPV), transient photocurrent (TPC), and the dependence of short-circuit current density and open-circuit voltage on light intensity reveal that the cold-manufacturing method can significantly prevent the heterojunction silicon cells from non-radiatively recombining after being cut. These results indicate that the edge-recombination of the silicon solar cells cut by grinding wheels is reduced compared with that cut by laser. As a result, statistical analysis of the device performance reveals that both the open-circuit voltage and fill factor of the device are improved, and the average photoelectric conversion efficiency increases by an absolute efficiency of ~1%. Stacking the obtained silicon cells with the normal transparent perovskite solar cells, the obtained four-terminal perovskite/silicon tandem solar cells deliver an efficiency of over 28%. This work emphasizes the importance of reducing efficiency loss during manufacturing the heterojunction silicon solar cell in fabricating high-performance silicon-based tandem solar cells.

Highly Efficient Bifacial Silicon/Silicon Tandem Solar Cells

Silicon-based tandem solar cells with efficient use of the solar spectrum are desirable for a next generation-commercial photovoltaic system. It has been widely investigated elsewhere using perovskites or III-V cells as top cell materials for high efficiency and stability. However, perovskite and III-V top cells are still unsuitable for mass production as well as expansion and integration with silicon solar cell production processes so far. Two-terminal bifacial Si/Si tandem cell by bonding with transparent conductive adhesive (TCA) is reported here. The current matching can maximize the efficiency by controlling the opening area of the top cell, which makes the bottom cell also able to absorb sunlight in the short wavelength region that is absorbed by the top cell as well, without being limited to the thickness or bandgap of the top cell. The Si/Si tandem solar cell achieved 25.195 mA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> of current density after current matching by 36% opening ratio of top cell.

Materials and Prospects of Novel Solar Cells

As industrial standards continue to grow, the demand for traditional energy sources is on the rise, the solar energy is clean and non-polluting, renewable energy sources. Solar cells are devices that can convert sunlight directly into electricity. Solar cells have progressively established themselves as a research hotspot sought after by scholars in recent years. This paper summarizes the device structure, principle, development status and problems faced by the traditional silicon crystal solar cells and novel solar cells. In addition, this paper also compares the cost, advantages and disadvantages, and the highest efficiency of these several solar cells, analyzes the advantages of the traditional silicon-based solar cells, and the future development direction of several new solar cells. Finally, this paper concludes that silicon solar cells are still dominant in the market because of their outstanding power conversion efficiency (PCE) and stability. The novel solar cells with thin-film structures have high theoretical conversion efficiency and some other characteristics, so they will hopefully replace the traditional silicon solar cells in the future. However, stability, PCE and cost are currently the main challenges.

Mechanisms of Silicon Surface Passivation by Negatively Charged Hafnium Oxide Thin Films

We have studied the mechanisms underpinning effective surface passivation of silicon with hafnium oxide (HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) thin films grown <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">via</i> atomic layer deposition (ALD). Plasma-enhanced ALD with O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> plasma and a tetrakis(dimethylamido)hafnium precursor was used to deposit 12 nm thick HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> films at 200 °C on high-lifetime 5 Ωcm <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> -type Czochralski silicon wafers. The passivation was activated by postdeposition annealing, with 30 min in air at 475 °C found to be the most effective. High-resolution grazing incidence X-ray diffraction measurements revealed the film crystallized between 325 and 375 °C, and this coincided with the onset of good passivation. Once crystallized, the level of passivation continued to increase with higher annealing temperatures, exhibiting a peak at 475 °C and yielding surface recombination velocities of <5 cm s <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> at 5 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">14</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup> injection. A steady decrease in effective lifetime was then observed for activation temperatures >475 °C. By superacid repassivation, we demonstrated this reduction in lifetime was not because of a decrease in the bulk lifetime, but rather because of changes in the passivating films themselves. Kelvin probe measurements showed the films are negatively charged. Corona charging experiments showed the charge magnitude is of order 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sup> qcm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> and that the reduced passivation above 475 °C was mainly because of a loss of chemical passivation. Our study, therefore, demonstrates the development of highly charged HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> films and quantifies their benefits as a standalone passivating film for silicon-based solar cells.

Electrical and Optical Properties of Boron Doped Zinc Oxide Thin-film Deposited by Metal-organic Chemical Vapour Deposition for Photovoltaic Application

Globally, there is a high demand for clean, sustainable and renewable energy for domestic and industrial use. Conventional photovoltaic cell technology relies heavily on crystalline silicon wafers which render silicon-based solar cells expensive due to the initial cost of production and required complex deposition methods. Due to these challenges, great research interest is now directed towards thin-film solar cells. In this work, the metal-organic chemical vapour deposition (CVD) method was chosen in the preparation of boron-doped zinc oxide (ZnO: B) thin film onto a glass slide substrate. The prepared ZnO: B thin films were characterized and optimized as a window layer for solar light trapping. The transmittance of the ZnO: B films varied between 70% and 81% for boron concentration ranging from 0.0 M to 0.06 M. With the increase in boron concentration, bandgap and resistivity of the ZnO: B varied from 2.96 to 3.72 eV and 120 Ω-cm to 58 Ω-cm, respectively. Based on the results obtained, we believe that ZnO: B is suitable as a window layer for solar light trapping in the fabrication of a photovoltaic cell.

Performance optimization of lead-free MASnBr3 based perovskite solar cells by SCAPS-1D device simulation

Perovskites are at the forefront of research into potential alternatives for bulky and costly silicon-based solar cells. In recent years, lead-based organic and inorganic perovskite solar cells have broken efficiency records. However, these have stability issues and may pose health risks in the long-term. Hence, there has been ideally inorganic perovskite solar cells and parallel search for lead-free to match and eventually surpass the achievements of lead perovskite analogues. This study reports a modelling-guided device optimization process to design highly efficient lead-free n-i-p methyl ammonium tin bromide (MASnBr3) perovskite solar cells. We have studied the effect of the various hole and electron transport layers on the performance of MASnBr3 devices. The influence of different parameters, such as doping concentration of optimized HTLs/ETLs, the thickness of the perovskite layer, NA/ND of the absorption layer, and the defect density, is thoroughly investigated using numerical simulations. An optimized device FTO/SnO2/MASnBr3/NiO/Au is proposed here with an open circuit voltage of 1.1214 V, a short circuit current density of 34.8654 mA/cm2, fill factors of 88.30%, a theoretical power conversion efficiencies of 34.52%, and quantum efficiencies of 98%. This work reveals the potential of the MASnBr3 material as a perovskite for toxicity-free renewable energy.

Atom-to-Device Simulation of MoO3/Si Heterojunction Solar Cell

Metal oxides are commonly used in optoelectronic devices due to their transparency and excellent electrical conductivity. Based on its physical properties, each metal oxide serves as the foundation for a unique device. In this study, we opt to determine and assess the physical properties of MoO3 metal oxide. Accordingly, the optical and electronic parameters of MoO3 are evaluated using DFT (Density Functional Theory), and PBE and HSE06 functionals were mainly used in the calculation. It was found that the band structure of MoO3 calculated using PBE and HSE06 exhibited indirect semiconductor properties with the same line quality. Its band gap was 3.027 eV in HSE06 and 2.12 eV in PBE. Electrons and holes had effective masses and mobilities of 0.06673, -0.10084, 3811.11 cm2V-1s-1 and 1630.39 cm2V-1s-1, respectively. In addition, the simulation determined the dependence of the real and imaginary components of the complex refractive index and permittivity of MoO3 on the wavelength of light, and a value of 58 corresponds to the relative permittivity. MoO3 has a refractive index of between 1.5 and 3 in the visible spectrum, which can therefore be used as an anti-reflection layer for solar cells made from silicon. In addition, based on the semiconducting properties of MoO3, it was estimated that it could serve as an emitter layer for a solar cell containing silicon. In this work, we calculated the photoelectric parameters of the MoO3/Si heterojunction solar cell using Sentaurus TCAD (Technology Computing Aided Design). According to the obtained results, the efficiency of the MoO3/Si solar cell with a MoO3 layer thickness of 100 nm and a Si layer thickness of 9 nm is 8.8%, which is 1.24% greater than the efficiency of a homojunction silicon-based solar cell of the same size. The greatest short-circuit current for a MoO3/Si heterojunction solar cell was observed at a MoO3 layer thickness of 60 nm, which was determined by studying the dependency of the heterojunction short-circuit current on the thickness of the MoO3 layer.

Transport mechanisms in hyperdoped silicon solar cells

According to intermediate band (IB) theory, it is possible to increase the efficiency of a solar cell by boosting its ability to absorb low-energy photons. In this study, we used a hyperdoped semiconductor approach for this theory to create a proof of concept of different silicon-based IB solar cells. Preliminary results show an increase in the external quantum efficiency (EQE) in the silicon sub-bandgap region. This result points to sub-bandgap absorption in silicon having not only a direct application in solar cells but also in other areas such as infrared photodetectors. To establish the transport mechanisms in the hyperdoped semiconductors within a solar cell, we measured the J–V characteristic at different temperatures. We carried out the measurements in both dark and illuminated conditions. To explain the behavior of the measurements, we proposed a new model with three elements for the IB solar cell. This model is similar to the classic two-diodes solar cell model but it is necessary to include a new limiting current element in series with one of the diodes. The proposed model is also compatible with an impurity band formation within silicon bandgap. At high temperatures, the distance between the IB and the n-type amorphous silicon conduction band is close enough and both bands are contacted. As the temperature decreases, the distance between the bands increases and therefore this process becomes more limiting.

The Shockley–Queisser limit and the conversion efficiency of silicon-based solar cells

According to some estimates, every hour, Sun provides planet Earth with more energy than humankind consumes in a whole year. Part of this energy has been essential to ensure living conditions (warmth and food production, for instance) and, more recently, to generate electricity by means of atmospheric (aeolian) and/or geographical (hydropower) sources. In addition to these, the direct (photovoltaic PV) conversion of solar radiation into electricity represents a very elegant method of power generation that causes minimum (or no) environmental disturbance. As a result, numerous efforts have been dedicated to further advance the achievement of clean and sustainable electricity, as supplied by the PV science and technology. Within this scenario, the association of PV with the silicon (Si) semiconductor industry played a crucial role–either by introducing new scientific insights or by promoting successive costs reductions in the field of renewable energy conversion. Yet, the performance of these so-called (either crystalline or amorphous) Si-based solar cells was always a matter of concern. In fact, the subject gained attention with the seminal work by Walter Shockley and Hans Queisser that, in 1961, proposed a model according to which the maximum efficiency of a solar cell is determined by both the solar spectrum and the properties of the semiconductor material. Since then, the work by Shockley and Queisser (also known as the Shockley–Queisser limit) has experienced some improvements and became a reference in the field. Motivated by these facts, along with the main scientific–technological achievements they provided, the Shockley–Queisser limit and the conversion efficiency of the Si-based solar cells along the last 60 years form the basis of this paper.

Efisiensi Counter Electrode Dengan Pengurangan Pemakaian Platina Menggunakan Komposit Bahan Ramah Lingkungan Grafin Dan Carbon Nanotubes Untuk Aplikasi Dye Sensitized Solar Cells

&lt;p&gt;&lt;span lang="EN-AU"&gt;Dye sensitized solar cells (DSSCs) are the most popular solar cells in the third generation. DSSCs have been widely developed as an alternative to silicon-based solar cells because of its easy manufacturing process, high efficiency, easy production costs, and environmental friendliness. Graphene and carbon nanotubes (CNTs) are promising materials to reduce the use of platinum (Pt) in counter electrode (CE) due to their excellent properties, such as thermal, electrical conductivity, and high surface area. One of the derivatives of graphene that is often used is reduced graphene oxide (rGO) which is produced from GO solution by a reduction process. GO was synthesized in an electrolyte containing surfactant by the electrochemical exfoliation method. The specially prepared sodium 1,4-bis(neopentyloxy)-3-(neopentyloxycarbonyl)-1,4-dioxobutane-2-silphonate (TC14) surfactant was used in GO synthesis. The CE thin film of TC14-rGO/CNTs/Pt hybrid shows the highest efficiency values (0.0594%) with Jsc, Voc, and FF of 0.176 mA/cm2, 0.622 V, and 0.464, respectively. This was believed due to the conjugated network in CNTs acts as a connecting cable between the TC14-rGO layers and as a vacancy filler, the high electrical conductivity value and the larger surface area also cause faster electron movement, making these properties important in DSSC performance. The FF value which is also the highest in the TC14-rGO/CNTs/Pt hybrid samples as CE is also influenced by its structure. The high surface area of CNTs and TC14-rGO in the TC14-rGO/CNTs/Pt hybrid samples exhibited important properties for generating dye after electron injection and led to a faster route of electron regulation during DSSCs processing. These findings indicate that Pt composited with environmentally friendly and inexpensive materials such as T14-rGO and CNTs can improve CE performance in DSSCs applications. Based on this, this research can be used as a basis for further research on the fabrication of carbon-based CE&lt;/span&gt;&lt;/p&gt;

Technoeconomic Analysis of Dye Sensitized Solar Cells (DSSCs) with WS2/Carbon Composite as Counter Electrode Material

Exploration of clean and renewable energy materials is necessary due to the coming energy crisis and environmental problems. Solar energy is one of the favorable energy sources because of the continuous energy reservoir and its affluence. Silicon-based solar devices are expensive due to their complicated production process, which limits this technology for urban and other commercial applications. Among the third generation of solar cells, Dye-Sensitized Solar Cells (DSSCs) have attracted widespread attention as potential cost-effective alternatives to silicon-based solar cells. In this paper, the commercializing potential of the DSSCs is investigated. A module is introduced where the materials, equipment, and distribution of direct manufacturing costs are calculated. The manufacturing costs and the Levelized Cost of Energy (LCOE) of these DSSCs for a system lifetime of 25 years were determined to be USD 22.40 per m2 and USD 0.0438 per kWh and the module price of this technology is USD 0.18 per W and the total installed system cost is USD 0.88 per W in Kansas which suggest that this PV technology could challenge other leading PV technologies.

A Review on Current State, Recent Developments and Future Prospects of Dye Sensitized Solar Cells

The sun is a primary abundant renewable source of energy for most of the life forms in our planet. By fully grasping the power of the sun, we can improve our way of life, reduce our dependence on fossil fuels or other types of energy sources and stimulate economy by bringing new jobs to all our planet industry. Among sustainable and renewable energy sources, solar cell, also known as photovoltaic cell, is one of the promising options of renewable energy and the most efficient. For the past several years, different photovoltaic devices like inorganic, organic and hybrid solar cells are invented for different application purposes. Regardless of its high conversion rate of silicon-based solar cells, the high module cost and complicated production process restricted their application. Research has been focused on alternative organic solar cells for their inherent low module cost and easy fabrication processes. Dye sensitized solar cell (DSSC) is considered to be one of the most promising, efficient, low-cost organic solar cells in recent years. DSSC, being transparent to some extent and comparatively cheaper than conventional solar photo-voltaic, can be a potential energy source for the future. This review paper focuses on the working of DSSC, its current state and recent developments in the various components of DSSC. The perspectives for the future development of the technology have also been discussed.

Ag Dendrites on W/C as Enhanced Active and Stable Electrocatalysts for Scalable Solar-Driven CO2rr

The electrochemical conversion of solar energy into competent chemicals is the most efficient technique to ensure clean and sustainable energy source for society in the future. In fact, solar cells can electrochemically produce electricity without pollution by converting CO2 into a variety of chemicals. The carbon dioxide reduction reaction (CO2RR) is an environmentally friendly approach to produce useful hydrocarbons such as carbon monoxide (CO), methane, ethylene, formates, etc and alcohols and remove exhausted CO2, which is a greenhouse gas. Conventionally, studies on the CO2RR have been conducted by using liquid-phase H-cells and a CO2-saturated electrolyte. However, it resulted in a low current density because the low solubility of CO2 in the liquid electrolyte occurs mass transfer limitation. To improve of the current density related to the CO2RR, two types of gas-fed CO2RR electrolyzers containing gas diffusion layer (GDL) electrodes have been proposed. The first type of CO2RR devices use a liquid electrolyte, the electrolyte increases CO2RR performance through controlling the cathode conditions, such as pH and anion concentration. The second type of CO2RR devices is zero-gap electrolyzers that use an anion exchange membrane (AEM) and humidified CO2 gas. AEM transmits carbonate and hydroxide ion, inducing favorable environmental for CO2RR. These zero-gap CO2 electrolyzers are attracting attention as the most promising system owing to several advantages such as extremely low ohmic resistance, scalable and stackable configuration, and commercial applicability, as affirmed by using a system consisting of a fuel cell and water electrolyzer. Among the products of the CO2RR, CO is particularly attractive as aspect of its economic benefits and large demand. Ag-based materials exhibit the most electrochemical performance for producing CO. and high selectivity. To enhance the catalytic activity of Ag-based catalysts, various approaches have been studied to change the surface electronic structure of Ag such as alloy formation, anion-based modification, shape control, near-surface structure and engineering. However, catalyst designs that do not consider the gas phase reactions cannot enough utilize their catalytic activity although recent progress has made in the development of Ag-based catalysts for the CO2RR. Therefore, considerable efforts must be preoccupied with the development of highly active, stable, and gas-transferable structured catalysts for gas-fed CO2RR electrolyzers with incoporating a GDL. Additionally, aming for the realization of clean technology for producing CO, we demonstrate the practicalbility of sunlight-driven CO2RR on a large scale using commercial silicon-based solar cells and zero-gap electrolyzers. Silicon-based solar cells are still the preferred commercially applicapable options for producing large amounts of electrical power from solar energy because of their scalability. In this study, we report a 3D silver dendrite on W/C (as denoted WC@AgD) catalyst with abundant nanograin boundaries that show enhanced CO2RR performance and stability. WC@AgD exhibited marked catalytic activity with a maximum CO partial current density of 400 mA cm-2 and durability for 100 h at 150 mA cm-2. We also fabricated an solar-to-CO (STC) conversion device combined with a silicon-based solar cell of 120 cm2 area and a zero-gap CO2 electrolyzer with an area of 10 cm2. The stand-alone photovoltaic-electrochemical system achieved a solar-to-CO efficiency (ηSTC) of 12.1 % at 1A under AM 1.5 G illumination and realistic outdoor conditions. The device design and electrode configuration extended viable route for implementing large-scale installations for solar-driven production of chemicals. Figure 1

Bending Pyrenacenes to Fill Gaps in Singlet-Fission-Based Solar Cells

Singlet fission is envisaged to enhance the efficiency of single-junction solar cells beyond the current theoretical limit. Even though sensitizers that undergo singlet fission efficiently are known, characteristics like low-energy triplet state or insufficient stability restrict their use in silicon-based solar cells. Pyrenacenes have the potential to overcome these limitations, but singlet-fission processes in these materials is outcompeted by excimer formation. In this work, bent pyrenacenes with a reduced propensity to stack and thus form excimers are computationally evaluated as singlet-fission materials. The energies of the S1, T1 and T2 states were estimated in a series of bent pyrenacenes by means of time-dependent density functional theory calculations. Our results show the opposite trend observed for perylene diimides, namely, an increase in the energy of the T1 and S1 states upon bending. In addition, we show that the energy levels can be tuned on demand by manipulating the bend angle to match the energy gap of various semiconductors that can be used in single-junction solar cells, making pyrenacenes promising candidates for singlet fission.

Enhancement in power conversion efficiency and stability of perovskite solar cell by reducing trap states using trichloroacetic acid additive in anti-solvent

Perovskite solar cells (PSCs) have shown significant commercial promise due to their fast development over the last decade and recent demonstration of a power conversion efficiency (PCE) almost equivalent to that of silicon-based solar cells. Shallow carrier trapping states within the bulk or surface of a perovskite layer are highlighted by researchers as a reason for the PSC efficiency losses. Suppressing the trap-induced shallow defects is a powerful strategy to improve the potential of perovskite materials for solar cell application. The current study planned on tailoring chlorobenzene (CB) anti-solvent with a trichloroacetic acid (TCAA) additive to prepare a favourable MAPbI3 layer with lower defects to record higher power conversion efficiency (PCE) in MAPbI3-based solar cells. Characterization results indicate the introduction of a few amounts of TCAA into CB affects the perovskite crystallization through reactions of the carboxyl group with the under-coordinated lead ions during the fabrication process. The TCAA-based PSCs show lower radiative and non-radiative charge recombination, leading to facilitated charge transport within the PSCs. It produces a champion PCE of 19.37% for the TCAA-based PSCs with a boosted stability behavior, which is greater than the control PSCs, which have a maximum PCE of 16.90%.