Fabrication Of Solar Cells Research Articles

Luminescence spectrum of cadmium chalcogenide photovoltaic film structures and their power enhancement

A technology has been developed for producing photovoltaic film structures of CdTe, CdTe:In, CdTe/CdS by thermal vacuum deposition, which allows increasing their operating power. An analysis of their low- temperature photoluminescence spectra shows a significant increase in their spectral sensitivity. It has been experimentally shown that there is a clear correlation between the anomalous photovoltaic (APV) properties and the shape of the intrinsic photoluminescence band of obliquely deposited CdTe films. The photoluminescence spectrum of a polycrystalline CdTe film with APV property is qualitatively different from the spectra of a single crystal, large-block polycrystal and single microcrystal. The main contribution to the photoluminescence of the film comes from radiative recombination of free carriers (A-line with half-width ΔEA≈14.2±0.1 meV) and edge luminescence with a wide doublet structure (B- and C - lines with half- widths 18.5±0.1 meV and 32.2±0.1 meV). When doped with In impurities and as a result of heat treatment, the emission spectrum is greatly transformed in accordance with the change in the photoelectric properties of the film. In the photoluminescence spectrum of a CdTe layer in a CdTe/CdS heterostructure grown under identical technological conditions as a CdTe monolayer, an additional broad spectral line appears due to the presence of a heterointerface, the superhot region disappears, and the A-emission line narrows somewhat (ΔEA≈11.2±0.1 meV), which significantly differ the studied film structures from the known CdS/CdTe heterosystems of other authors. The proposed method for analyzing low-temperature photoluminescence spectra makes it possible to purposefully control the technology for manufacturing photovoltaic film structures. The results obtained are of interest for film optoelectronics and solar cell manufacturing.

Enhancing perovskite solar cell performance through PbI2 in situ passivation using a one-step process: experimental insights and simulations.

The in situ passivation of a methylammonium lead triiodide (MAPbI3) phase spin-coated via a one-step process was experimentally investigated to elucidate their fundamental properties. Structural analysis revealed that MAPbI3 adopts a tetragonal crystal structure with a small excess of PbI2 (0.03 M) segregating at grain boundaries. Optical characterization indicated a band gap of 1.53 eV, highlighting the material's potential as an effective visible light absorber. To facilitate the fabrication of efficient perovskite solar cells (PSCs), we employed a primary n-i-p planar structure (ITO/SnO2/MAPbI3/spiro-OMeTAD/Au) in drift-diffusion SCAPS-1D simulations using experimental data from MAPbI3 layers containing excess PbI2. The simulations predicted a high power conversion efficiency (PCE) of approximately 24%. We further analyzed the impact of series resistance, shunt resistance, MAPbI3 thickness, defect density, as well as radiative and Auger recombination on photovoltaic performance, aiming to identify optimal parameters for enhanced device efficiency. Additionally, the use of ohmic contacts with AZO and IZO as the front and rear contacts, respectively, in the optimized device structure (AZO/SnO2/MAPbI3/spiro-OMeTAD/IZO) resulted in a PCE of 26.03%. These findings provide valuable insights for future research aimed at achieving high-efficiency bifacial MAPbI3 perovskite solar cells.

Recent trends on the application of phytochemical-based compounds as additives in the fabrication of perovskite solar cells

Phytochemical-based additives have functional groups that can modulate the nucleation and crystallization process of perovskite films resulting in improved optoelectronic and degradation resistance.

An ambient process for hole transport layer-free highly stable MAPbI3 by addition of MACl for efficient perovskite solar cells

An ambient process for the fabrication of HTL-free carbon-based perovskite solar cells at room temperature with the addition of an optimized amount of MACl into the perovskite precursor solution.

DLTS analysis of interface and near-interface bulk defects induced by TCO-plasma deposition in carrier-selective contact solar cells

We investigate the electrical characteristics of defects at the SiO2/Si interface, within the adjacent Si crystal, and through the depth profile of the bulk defect using three-dimensional deep-level transient spectroscopy (3D-DLTS). These defects are introduced by the reactive plasma deposition technique employed for depositing transparent conductive oxides in the fabrication of carrier-selective contact-type solar cells. To control the surface potential near the Si surface, we apply a varying voltage to obtain DLTS signals as functions of both temperature and Fermi level at the SiO2/Si interface. Using machine learning for 3D-DLTS spectral analysis, we estimate the capture cross sections, energy levels, densities, and depth profiles of these process-induced defects. The experimental results indicate the existence of three types of electron traps within the bulk defects, ranging from the interface to a depth of ∼70 nm. The electrical properties of these bulk defects suggest the presence of oxygen-related defects within Si. On the other hand, regarding the properties of interface defects, the capture cross sections and the defect densities are estimated as a function of their energy levels. They suggest that the defects at the SiO2/Si interface are likely oxygen-related PL centers.

Solution-based electrical doping of organic photovoltaics with non-fullerene acceptors facilitated by solvent vapor pre-treatment

Solution-based electrical doping of organic semiconductors using 12-molybdophosphoric acid (PMA) hydrate has been shown to allow p-type doping of conjugated polymers over a limited depth from the surface, enabling the fabrication of organic solar cells with a simplified device architecture. However, the doping level of certain conjugated polymers using PMA was found to be limited by the polymer film volume. Here, we report a modified PMA doping technique based on film volume expansion that is applicable to device fabrication, leading to hole-collecting layer-free non-fullerene organic photovoltaic devices, which exhibit a comparable photovoltaic performance to those with a commonly evaporated MoO3 hole-collecting layer.

Fabrication of high-performance flexible perovskite solar cells based on synergistic passivation strategy

Flexible perovskite solar cells have attracted much attention in the scientific community due to their lightweight nature, high flexibility, and superior power-to-mass ratio. One of the most effective strategies for enhancing the power conversion efficiency of these cells involves addressing grain boundary defects within the perovskite films and interfacial defects between the perovskite films and charge transport layers. In this work, we optimize the performance of inverted flexible perovskite solar cell by using octadecylamine hydrochloride (OACl) as both an additive and a surface passivating agent to achieve synergistic passivation to the bulk phase and surface. The incorporation of OACl in the perovskite precursor solution results in the enlarging of the perovskite crystal grains, enhancing crystallinity, and passivating of grain boundary defects within the perovskite film. This optimization leads the open-circuit voltage to increase from 1.07 to 1.12 V, fill factor from 70.86% to 75.04%, and power conversion efficiency from 18.08% to 20.12%. In addition, the OACl solution is used to passivate the surface of perovskite film, resulting in a smoother perovskite surface, fill the grain boundaries, and reduce the defect density on the perovskite surface. As a result, the optimized device exhibits an open-circuit voltage of 1.15 V, fill factor of 76.15%, and ultimately achieves a power conversion efficiency of 20.80% for flexible perovskite solar cells. The synergistic passivation strategy based on OACl used in this work provides an effective approach for fabricating efficient flexible perovskite solar cells.

Research progress of green antisolvent for perovskite solar cells.

Conventional antisolvents such as chlorobenzene and benzotrifluoride are highly toxic and volatile, and therefore not preferred for large-scale fabrication. As such, green antisolvents are favored for the eco-friendly fabrication of perovskite films. This review primarily discusses the impact of various green antisolvents on the fabrication of thin perovskite films and analyzes the main chemical characteristics of these green antisolvents. It also interprets the impact of green antisolvent treatment on crystal growth and nucleation crystallization mechanisms. It introduces the effective fabrication of large-area devices using green antisolvents and analyzes the mechanisms by which green antisolvents enhance device stability. Subsequently, several green antisolvents capable of preparing highly stable and efficient devices are listed. Finally, we outline the key challenges and future prospects of antisolvent treatment. This review paves the way for green fabrication of industrial perovskite solar cells.

Fabrication of Double Antireflection Layer of SiO2/SiNx via Spin Coating and Brush Painting for Enhanced Performance of Silicon Solar Cells

This research investigates the optical, structural, and photovoltaic attributes of a dual antireflection (AR) layer deposition on crystalline silicon (c–Si) solar cells using second SiO2 layer on SiNx AR. The second SiO2 AR layer on a SiNx AR-based c–Si solar cell was fabricated utilizing both spin coating and brush painting techniques, resulting in a unique double (SiO2/SiNx) AR layer. The initial SiNx AR layer was deposited on the c–Si solar cell through plasma-enhanced chemical vapor deposition (PECVD), while the SiO2 layer was subsequently applied using two different methods such as spin coating at 5000 rpm for 20 s and brush painting, separately, on Si solar cell. The double (SiO2/SiNx) AR layer on the Si wafer exhibited a substantial reduction in average reflectance, approximately 6.02% through spin coating and 5.17% through brush painting, within the wavelength range of 400–1000 nm when compared to a textured silicon wafer. The fabricated solar cell featuring the double (SiO2/SiNx) AR layer, achieved a power conversion efficiency of 15.21% and 17.57% for spin coating and brush painting, respectively. The utilization of the double (SiO2/SiNx) AR layer through brush painting on the Si solar cell not only provided low reflectance but also demonstrated excellent surface properties, making it a promising candidate for the cost-effective fabrication of high-performance Si solar cells.

DSSC Fundamentals and Optimization Materials :A Review

Recently, researchers are focusing on renewable energy sources such as wind energy, Hydro-thermal energy, and solar energy. In this research article DSSC fundamentals and optimized materials are discussed and compared. The maximum efficiency reported by the researcher is 12% using Ru (II) dyes. The efficiency of DSSC depends on the various factors such as working electrode material, counter electrode material, dye used in preparation of solar cell are discussed. The simplest technique used for fabrication of DSSC solar cell is doctor blade method also discussed in this review article.

Water-based layer-by-layer processing enables 19% efficient binary organic solar cells with minimized thickness sensitivity

A mesoporous layer was constructed by a donor-based nanoparticulate water-ink, which facilitates the infiltration of the acceptor, allowing the fabrication of efficient organic solar cells with a high thickness tolerance.

Band gap tuning of perovskite solar cells for enhancing the efficiency and stability: issues and prospects.

The intriguing optoelectronic properties, diverse applications, and facile fabrication techniques of perovskite materials have garnered substantial research interest worldwide. Their outstanding performance in solar cell applications and excellent efficiency at the lab scale have already been proven. However, owing to their low stability, the widespread manufacturing of perovskite solar cells (PSCs) for commercialization is still far off. Several instability factors of PSCs, including the intrinsic and extrinsic instability of perovskite materials, have already been identified, and a variety of approaches have been adopted to improve the material quality, stability, and efficiency of PSCs. In this review, we have comprehensively presented the significance of band gap tuning in achieving both high-performance and high-stability PSCs in the presence of various degradation factors. By investigating the mechanisms of band gap engineering, we have highlighted its pivotal role in optimizing PSCs for improved efficiency and resilience.

The Current State of Research in the Field of Obtaining Semiconductor Materials and Prospects for Development

Due to the increase in the world's population and production volumes, the demand for energy is also increasing year by year. The use of solar energy is one of the most effective ways to solve the energy problems of the countries of the world, as well as our Republic. Solar energy is one of the cheap and environmentally friendly resources, and it is important to create cheap and promising solar cells based on inorganic and organic semiconductor materials. Research and development work is being carried out around the world aimed at the creation and production of new solar cells based on semiconductor polymers and phthalocyanine-based dyes. In this regard, solar cells obtained from light-sensitive dyes based on semiconductor polymer materials, metal and non-metal atoms, and phthalocyanine dyes are among the solar cells currently available due to their flexibility, simple design, environmental friendliness and economy. Improving the efficiency of composites based on organic semiconductor compounds, determining their physico-chemical and operational properties, identifying semiconductor polymers and phthalocyanine-based dyes that can replace silicon-based solar panels put into production as solar cells a large-scale research and development work is being carried out on the use of solar elements in the extraction of solar cells.

Atomic insights into the interaction of N2, CO2, NH3, NO, and NO2 gas molecules with Zn2(V, Nb, Ta)N3 ternary nitride monolayers.

The search for promising carrier blocking layer materials with high stability, including resistance to surface inhibition by environmental molecules that cause a drop in carrier mobility, is critical for the production of tandem solar cells. Based on density functional theory calculations, the reaction of atmospheric gases, including N2, CO2, NH3, NO, and NO2, with three promising Zn2(V, Nb, Ta)N3 monolayers is discovered. The results suggest the chemical adsorption of NH3 and physical adsorption of NO and NO2. In addition, the Zn2(V, Nb, Ta)N3 monolayers are characterized by a weak bonding with N2 and CO2. Charge redistribution is found at the interface between the monolayers and NH3, NO and NO2 molecules, leading to the formation of a local surface dipole that affects the functionality of the Zn2(V, Nb, Ta)N3 monolayers. The Zn2VN3 monolayer is less reactive with atmospheric gases and thus is the most promising for application in tandem solar cells. Notably, the revealed nontrivial behavior of the Zn2(V, Nb, Ta)N3 monolayers towards N-containing gases makes them promising for application in gas sensing. Specifically, the Zn2TaN3 monolayer is the most promising for application in molecular sensing due to its high reversibility and distinguished interaction with NH3, NO, and NO2 gases.

From particles to films: production of Cs2AgBiBr6-based perovskite solar cells and enhancement of cell performance via ionic liquid utilization at the TiO2/perovskite interface.

Herein, Cs2AgBiBr6 particles produced by the traditional super-saturation precipitation method were used as precursors to create Cs2AgBiBr6 films by the gas-quenching process under ambient atmospheric conditions. These films were utilized as a light-absorbing layer in hole-transporting free perovskite solar cells (PSCs) with carbon electrodes. Furthermore, the incorporation of the 1-butyl-3-methylimidazole hexafluorophosphate (BMIMPF6) ionic liquid (IL) at the metal oxide electron transporting layer/perovskite interface resulted in enhanced crystallinity of the perovskite, forming large perovskite grains of up to 800 nm. However, it was discovered that establishing the optimal concentration for passivating surface defects takes precedence over encouraging the growth of larger perovskite grains. The utilization of the optimized BMIMPF6 concentration led to a remarkable increase in the power conversion efficiency (PCE) of the cell, with a boost of over 31% to reach 1.67%, when compared to the cell produced without the inclusion of the IL. Our findings underscore that the passivation of surface defects between the TiO2 and perovskite layers holds more importance for enhancing the PCE of Cs2AgBiBr6-based perovskite solar cells than focusing solely on the perovskite morphology.

Investigation of optical, dielectric, and conduction mechanism in lead-free perovskite CsMnBr3.

Metallic perovskites have advantageous optical and electrical properties, making them a valuable class of semiconductors for the manufacturing of solar cells. CsMnBr3 is notable among them due to its important optical characteristics. The electrical and dielectric characteristics as a semiconductor are examined in this study. Direct transitions with a 3.29 eV bandgap and an Urbach energy of 0.96 eV are revealed by the results. Through AC conductivity, it demonstrated semiconductor characteristics at 443 K. The dielectric loss varied with frequency and peaked at high frequencies. Furthermore, as temperature rose, a relaxation peak in the electrical modulus was seen to migrate to higher frequencies. Ac conductivity is described by the double power law expression. The conduction in our compound is governed by small polaron tunneling. Based on the optical results reported in the bibliography for this sample, we realize the importance of examining the electrical characteristics to comprehend the semiconductor behavior of CsMnBr3.

Efficient monodisperse upconversion composite prepared using high-density local field and its dual-mode temperature sensing.

Enhanced upconversion via plasmonics has considerable potential in biosensors and solar cells; however, conventional plasmonic configurations such as core-shell assemblies or nanoarray platforms still suffer from the compromise between the enhancement factor and monodispersity, which has failed to meet the requirement of the materials for the in vivo all-solution-prepared solar cells and biosensors. We herein report a monodisperse metal-dielectric-metal (MDM) type upconverted hybrid material with high efficiency. The lanthanide-doped upconversion nanoparticles (UCNPs) were sandwiched by two gold nanodisk mirrors, and the highly localized excitation field around the UCNPs together with the efficient coupling enhanced the upconversion. The upconversion intensity can then be effectively regulated and improved by three to four orders of magnitude. As per the measurement of the temperature-dependent fluorescence intensity and spectra shift, a dual-mode nanothermometer based on our proposed hybrid materials was demonstrated. This MDM-type upconverted hybrid material demonstrated the merits of high efficiency and monodispersity, which demonstrated promise in in vivo biosensors and solar cell fabrication techniques such as spin-coating and roll-to-roll.

Wet chemical poly-Si(n) wrap-around removal for TOPCon solar cells

This work gives an overview on different technological solutions for polysilicon removal in industrial tunnel oxide passivated contact (i-TOPCon) n-type silicon solar cell fabrication. The removal of parasitically deposited poly-Si layers on the front and the edges is a mandatory requirement for a low reverse bias junction leakage current (Irev). A polysilicon removal study on wafer level shows (i) that the efficient removal of the surface oxide layer before poly-Si etching is crucial to achieve short etching times and (ii) that an additive in the KOH solution enhances etching selectivity between poly-Si and silicon oxide surfaces. To evaluate the impact on device level, TOPCon cells have been fabricated in parallel using in-situ n-doped PECVD and LPCVD layers, as well as ex-situ LPCVD poly-Si layers, with another variation of poly-Si removal processes, namely wet chemical inline, wet chemical batch cluster and atmospheric dry etching (ADE). Our results show that a two-minute inline polysilicon removal in hot KOH meets the Irev qualification in case of as deposited in-situ doped layers, whereas for ex-situ doped layers a batch process with a five-minute KOH etching time is needed. LPCVD poly-Si cells show efficiencies above 23%, PECVD poly-Si cells with a batch cluster poly-Si removal process up to 23.4%.

Virtual Material Quality Investigation System

It is often difficult to inspect the material quality in the procurement process. In many cases, the true quality may only be revealed after several manufacturing processes or at the final test of the finished goods. This study employs a hybrid strategy consisting of predictive analytics and prescriptive analytics. The former considers the production characteristics and estimates the probability distribution of the material quality using a simulation optimization technique known as optimal computing budget allocation. The latter optimizes the feeding portfolio of the material allocation into the production line according to the customer's order specification. This study develops a virtual material quality investigation (VMQI) system considering the hybrid strategy and including four modules. An empirical study of a solar cell manufacturer in Taiwan validates the proposed VMQI system. The results show that the VMQI system improves the solution quality by at least 30% and potentially reduces the production cost by 19.8%.

Bükümlü Işıkların Yarıiletken Üzerindeki Elektriksel Etkisinin Deneysel Olarak İncelenmesi

Orbital Angular Momentum (OAM) beams are a special type of light that disrupts the circular symmetry of the optical field and carries the angular momentum of light. These beams enable new applications in optical devices and communication. In addition, as a result of their interaction with matter, OAM beams can transfer both photon energy and angular momentum, enabling the formation of higher currents. Thus, it has been shown that OAM beams can be used to obtain higher energies in increasing photovoltaic efficiency. The effect of OAM beams on photovoltaic efficiency has been a research topic in recent years. Some studies have theoretically shown that OAM beams can increase the electrical production of solar cells. The reason for this is that OAM beams impart angular momentum to electrons in addition to photon energy. The aim of this study is to experimentally investigate the electrical effect of an OAM beam spot produced using an SLM (Spatial Light Modulator) on a semiconductor solar panel. Higher currents were obtained by dropping the OAM beam onto photovoltaics. The current increase was 18.2%.