Properties Of Solar Cells Research Articles

Magnetic field modulation effect of photoelectric properties in dye-sensitized solar cells with La0.67(Ca,Ba)0.33MnO3 as counter electrodes.

In recent years, many semiconductor materials with unique band structures have been used as Pt counter electrode (CE) substitutes for dye-sensitized solar cells (DSSCs), which makes the photoelectric properties of DSSCs possible to be modulated by electric field, magnetic field, and light field. In this work, La0.67(Ca Ba)0.33MnO3 (LCBMO) thin film is employed to act as CE in DSSCs. The experimental results indicate that short-circuit current density and photoelectric conversion efficiency present better stability when applying an external magnetic field to the DSSCs. Furthermore, both the exchange current density (J0) and limit diffusion current density (Jlim) are largely enhanced by an external magnetic field. J0 increases from -0.51 mA•cm-2 to -0.65 mA•cm-2, and Jlim increases from 0.2 mA•cm-2 to 0.3 mA•cm-2 when applying a magnetic field of 0.25 T. The fitting results of the impedance test verify that the magnetic field reduces the value of Rct. Both magnetic-field enhancing catalytic activity and CMR effect jointly promote the increase of photocurrent and finally improve the photovoltaic effect in DSSCs.

Boosting the open-circuit voltage of Cu2ZnSn(S,Se)4 solar cell by Cd/NH3 soaking

In this paper, the open-circuit voltages (V OC) of Cu2ZnSn(S,Se)4 (CZTSSe) solar cells were improved by soaking the CZTSSe films in Cd/NH3 solutions before the deposition of buffer layers. The effects of Cd/NH3 soaking on the properties of CZTSSe films and solar cells were investigated in depth. We found Cd/NH3 soaking can promote downward band bending of the CZTSSe layer at the surface region. In addition, the Cd/NH3 soaking can eliminate the deep level acceptor in CZTSSe and decrease the density of the defects at the absorber/buffer interface. These effects can significantly reduce the carrier recombination in the depletion region of CZTSSe solar cells. As a result, the V OC of CZTSSe solar cells were increased from ∼460 mV to ∼480 mV, the efficiency of the best CZTSSe solar cell was increased from 10.2% to 11.6% by the Cd/NH3 soaking process.

Schottky junction based solar cell behavior of trichome hierarchical SnO2 nano-structures

Hydrothermally grown SnO2 hierarchical trichome nano-flowers (T-NFLs) have been examined for their device performance compared to nano-flakes (NFs), in part to meet the growing need for metal-oxide based solar cells. The structural analyses reveal superior lattice strain and free energy in the tetragonal phase of the T-NFLs over NFs. The band gap widening and oxygen defect-dominated luminescence in the visible range are observed from photoluminescence measurements. Compared to NFs, the Schottky current-voltage characteristics of the T-NFLs show improved Schottky barrier height (0.82 eV) with an ideality factor of 3.52 under dark and better solar cell properties with a conversion efficiency of 1.78 ± 0.03% under 1 sun illumination. The observed high open-circuit voltage of 1.56 V resulted from the decrement rate of carrier recombination, making the transparent metal oxide nano-material SnO2 T-NFLs suitable for solar cells and fast electronic applications.

Effects of mesoporous TiO2 with addition of V2O5 and rinsing with various solvents on the properties of dye-sensitized solar cells

Dye-sensitized solar cells (DSSC) have received much attention since they are simple, easily manufactured, inexpensive, and offer reasonable conversion efficiency. Mesoporous TiO2 with the addition of V2O5 nano-particles (0, 0.5, 1.0, 1.5 and 2.0 wt%) as a photoanode in DSSC have been successfully fabricated using a spin-coating method. Titanium tetrachloride (TiCl4) was used to synthesize a thin TiO2 blocking layer to enhance the performance of TiO2 photoanode in DSSC. After annealing treatment at 450 °C, the TiO2 blocking layer showed an amorphous structure. Performance was examined after soaking N719 dye and rinsing with five different solvents (ethanol, isopropanol, acetone, methanol, and diethyl ether). The results show that removing unanchored dye molecules using acetone solution can increase the specific surface area and dye adsorption amount of TiO2, resulting in good Jsc and photovoltaic efficiency. A conversion efficiency of 8.5% was achieved using fluorine doped tin oxide glass, a thin blocking layer, mixing 0.5 wt% V2O5 with mesoporous TiO2 and rinsing with an acetone solution.

Impact of absorber layer thickness and defect density on the performance of MAPbI3 solar cells based on CuO2 as hole transport material

Perovskite solar cells are a promising next-generation solar energy harvester because of their excellent photovoltaic performance and simple fabrication procedure. The high power conversion efficiency of this cell, together with its low cost of materials and processes, differentiates it from commercial silicon or other organic and inorganic solar cells. In this work, numerical simulation was performed using Solar Cell Capacitance Simulator (SCAPS)−1D for the device structure (FTO/HTM/ CH3NH3PbI3/ETM/Au) to analyze the impact of absorber layer thickness and defect density on various parameters of Photovoltaic cells. The purpose of this research was to explore the properties of CH3NH3PbI3-based solar cells with different HTM layers, such as Cu2O and ETM layers, such as SnO2, TiO2, and ZnO, respectively. Additionally, the thicknesses of the perovskite absorber are adjusted to obtain the highest photovoltaic efficiency, and the impact of the defect at the perovskite absorber layer on solar cell performance is also investigated. According to the findings of this article, the thickness of the absorber layer and defect density in a perovskite solar cell had a significant impact on JSC, FF, VOC, and efficiency. The findings show a substantial gain in efficiency (18%) when the ETM layer is ZnO. As the defect density of the absorber layer increases, the JSC, VOC, FF, and PCE values of perovskite solar cells decrease considerably. According to our findings, the ZnO as ETM is the most likely to provide a high photovoltaic (PV) efficiency when combined with Cu2O-based HTM.

Polar molecule as passivation agent towards enhanced carrier transport properties in perovskite solar cells

Defect passivation using aryl ammonium salts have been proved as a feasible way to promote the efficiency and stability of perovskite solar cells (PSCs). However, the design criterion is still no clear. Herein, a series of diammonium iodides were used as passivators on the perovskite surface. We find that in situation of diammonium salts, carrier transport ability is more important than their pKa values. And passivator molecules with high polarity would lead to improved carrier transport and then mitigated nonradiative recombination in PSCs due to the enhanced induced electric field and high carrier mobility. As a result, cell 3 (passivator with a pKa of 3.69 and high polarity) show superior PCE (21.59%) and stability than the control PSCs, but other devices with low polarity passivators show worse transport and poorer performance, despite their higher pKa (cell 4 and 5) or better energy level (cell 1). This work proposes a way to design passivators with enhanced carrier transport properties for PSCs.

Organic Solar Cells: An Analysis of AC and DC Electrical Properties

In this paper, AC and DC electrical properties of organic solar cells based on P3HT:PCBM active layer have been investigated. The performance of such solar cell has demonstrated the efficiency of 2.31% corresponding with short-circuit current density of 6.08 mA ⋅ cm[Formula: see text], open circuit voltage of 0.64 V and fill factor of 60%. The equivalent circuit and the properties of the supposed interfaces between the layers in the P3HT:PCBM-based solar cell have been estimated. AC properties have demonstrated series capacitance increasing with increasing frequencies, which means series capacitance saves charges and parallel capacitance has decreased with increasing of frequency work as discharge part of charges stored in series capacitance. Also, equivalent series and parallel resistances have demonstrated a decrease from 7 [Formula: see text] and 120 k[Formula: see text] at low frequency to 1 [Formula: see text] and 43 k[Formula: see text] at high frequencies, respectively.

Unraveling the Energetic Landscape of Perovskite Solar Cells: A Synergy of 2D Drift‐Diffusion Simulations and Tapered Cross‐Section Photoelectron Spectroscopy

Interfaces are crucial elements that define the electronic properties of perovskite solar cells (PSCs). However, obtaining the band structure of a full PSC and accessing its buried layers and interfaces without modifying the device is challenging. A tapered cross section (TCS) of a PSC (i.e., a PSC polished under a very shallow angle) offers access to these buried parts on a width one or two orders of magnitude larger than the lateral resolution of a photoelectron spectroscopy (PES) set‐up. Herein, 2D numerical drift‐diffusion simulations are combined with TCS‐PES measurements to access the electrostatic potential profile with high spatial resolution along the PSC, allowing us to construct the band diagram of device. Thus, it is confirmed experimentally that the presence of a band bending at the interfaces between perovskite and charge‐transport layers and quantified under various conditions relevant to solar cell operation. Such synergy between the TCS‐PES approach and numerical simulation provides substantial information about the energetic landscape at the interfaces in PSCs and is essential for devices without mostly field‐free layers. These insights for dark and illuminated conditions are central to understand the nature of interfaces within PSCs.

Surface modification of perovskite with guanidine hydro-chloride to improve the stability and efficiency of Cs0.2FA0.8PbI2·8Cl0.2 perovskite solar cells

Surface modification engineering has been established as a successful method for enhancing the properties of organic-inorganic perovskite solar cells (PVK–SCs). In this research, scientists employed guanidine hydrochloride (GuHCl) to modify the surface of Cs0.2FA0.8PbI2·8Cl0.2 perovskite (PVK:GuHCl) films, leading to a significant enhancement in the performance of the devices. After the surface modification, the PVK-SC demonstrated notable enhancements in its open-circuit voltage (Voc), which increased from 1.011 V to 1.056 V. Additionally, the power conversion efficiency (PCE) experienced a significant boost, surging from 13.1% to an impressive 18.6%. Additionally, the study highlighted that the reliability of the solar cell was greatly enhanced through surface engineering, as evidenced by the packaged device maintained an exceptional 90% of its initial value even after being stored at room temperature for six days.

Systematic Investigation of the Optoelectronic Properties of GaAs Nanowire and Nanocone Solar Cells: Effect of Geometrical Nonuniformities, Angle of Incidence, and Structural and Electronic Parameters

Systematic Investigation of the Optoelectronic Properties of GaAs Nanowire and Nanocone Solar Cells: Effect of Geometrical Nonuniformities, Angle of Incidence, and Structural and Electronic Parameters

Theoretical investigation on the influence of electron-accepting substitutions in modulating the optoelectronic properties of dye-sensitized solar cells

we explore the efficiency of D-π-A organic dyes in dye-sensitized solar cells (DSSCs). Five dyes with varied acceptor sizes and geometric structures are studied. Quantum mechanics calculations, utilizing density functional theory (DFT) and time-dependent density functional theory (TD-DFT), are used to assess their efficacy. Each dye has a simple push-pull architecture, featuring an arylamine electron donor and a furan conjugated spacer, with different acceptor groups incorporated. By fabricating high-efficiency DSSCs with these designed dyes, we evaluate their performance as light-harvesting sensitisers. Key parameters, such as short-circuit current density, open-circuit voltage, light-harvesting efficiency (LHE), electronic injection-free energy (ΔGinject), and regeneration driving forces (ΔGreg), are studied using quantum mechanics calculations. Our aim is to gain insights into the potential of these dyes to enhance the efficiency of DSSCs. By analyzing their structural and functional properties, we can better understand their effectiveness as sensitisers. This research contributes to the expansion of cost-effective and highly efficient dye-sensitized solar cells.

Experimental investigation of the impact of conducting polymer interlayer and iodine doping on the electronic properties of hybrid solar cells based on alkylated sexithiophene and nanostructured zinc oxide

Experimental investigation of the impact of conducting polymer interlayer and iodine doping on the electronic properties of hybrid solar cells based on alkylated sexithiophene and nanostructured zinc oxide

First-principles study of electronic properties of two-dimensional metal mixed perovskites solar cell and water resistance performance

Two-Dimensional (2D) layered hybrid organic-inorganic perovskite (HOIP) materials have been considered as potential photoconductive materials for solar cells owing to extraordinary conversion efficiency and easy preparation process. In this study, we perform first-principles design on metal mixed 2D HOIPs (BA2(Cs1-x Rb x )2Sn1.5Pb1.5I10 with different proportions of composition (x = 0, 0.5 and 1)) to investigate their electronic properties and stability against moisture. We find that the band gap and effective mass of BA2(Cs1-x Rb x )2Sn1.5Pb1.5I10 increases as the concentrations of mixed Rb atoms increases. Moreover, the result of calculated adsorption energy indicates that the metal mixed 2D HOIPs with different composition ratios of Rb atom exhibit better capacity on the resistance of water than the pure one (BA2MA2Sn3I10). The metal mixed 2D HOIPs shows great potential to be a new generation of solar cell with low-cost, suitable band gap, high thermal stability, and desirable power conversion efficiency.

Exploration of charge transfer analysis and photovoltaics properties of A-D-A type non-fullerene phenazine based molecules to enhance the organic solar cell properties

To intensify the photovoltaic properties of organic solar cells, density functional theory (DFT) based computational techniques were implemented on six non-fullerene A-D-A type small molecules (N1–N6) modified from reference molecule (R) which consists of phenazine fused with 1,4- Dimethyl-4H-3,7-dithia-4-aza- cyclopenta [α] pentalene on both sides with one of its phenyl rings acting as the central donor unit, further attached with 2-(5,6-Difluoro-2-methylene-3-oxo-indan-1-ylidene)-malononitrile acceptor groups at terminal sites. All proposed compounds have a phenazine base modified with a variety of substituents at the terminals. Transition density matrix, density of states, frontier molecular orbitals, intramolecular charge transfer abilities and optoelectronic properties of these compounds were investigated using B3LYP/6-31G (d, p) and B3LYP/6-31G++ (d,p) level of theory. All six designed compounds exhibited a bathochromic sift in their λmax as compared to the R molecule. All designed molecules also have reduced band gap and smaller excitation energy than R. Among all, N6 exhibited highest λmax and lowest bandgap as compared to reference molecule indicating its promising photovoltaic properties. Decreased hole and electron reorganization energy in several of the suggested compounds is indicative of greater charge mobility in them. PTB7-Th donor was employed to calculate open circuit voltage of all investigated molecules. N1–N5 molecules had improved optoelectronic properties, significant probable power conversion efficiency as evident from their absorption aspects, high values of Voc, and fill factor, compared to R molecule. Designed A-D-A type NF based molecules make OSCs ideal for use in wearable devices, building-integrated photovoltaics and smart fabrics.

Improving the efficiency of Cu2ZnSn(S,Se)4 solar cell by using localized K-doped precursor film

In this paper, we prepared Na–K co-doped Cu2ZnSn(S,Se)4 (CZTSSe) films by solution method. By optimizing the distribution of the K-doping (uniform or localized K-doping) in the precursor films, the efficiencies of CZTSSe solar cells were improved. The effect of the K-doping distribution on the properties of CZTSSe films and solar cells were investigated. Compared to the solar cells without K-doping, the uniform K-doping in the precursor film increased the solar cell efficiency from 10.4% to 11.7%. In comparison, the localized K-doping in the bottom and in the top of the precursor films yielded solar cells with efficiencies of 12.4% and 10.1%, respectively. It was determined that the K-doping distribution primarily had an influence on carrier recombination in the depletion regions of CZTSSe solar cells. Whereas k-doping at the top of the precursor film greatly enhances the carrier recombination in the depletion region, the bottom doping has the opposite effect. The reason could be that the variation of the K-doping distribution modified the crystallization of the CZTSSe films. As the result, the defect properties of the CZTSSe films were altered. Moreover, the effect of the bottom K-doping on the back contact properties of CZTSSe solar cells was investigated by impedance spectroscopy. Though the K-doping can reduce the back contact barrier of the solar cell, the back contact barrier still achieved the height of 228 meV. The results indicated that the back contact barrier would be an important limiting factor for the efficiency of CZTSSe solar cell.

Comparative Study of Polarization‐Dependent Conversion Efficiency of GaAs and Si Solar Cells at Oblique Incident Angles Using Surface DLAR Coating of MgF2/ZnSe

AbstractThe aim of this work is to minimize reflection losses in order to increase the efficiency of solar cells by using anti‐reflection coatings (ARCs). Despite extensive research on improving solar cell conversion efficiency at normal incidence, development at angle of incidence has received little attention. Thus, the reflectivity of single‐layer ARC (SLARC) MgF2 and ZnSe, double‐layer ARC (DLARC), MgF2/ZnSe on Si, and GaAs substrates at transverse electric (TE) and transverse magnetic (TM) modes of polarization in the visible and near‐IR regions for different angles of incidence is analyzed. The optical and electrical properties of Si and GaAs solar cells are analyzed by using the reflectance spectra of SLARC and DLARC at various angles of incidence for the TM and TE modes of polarization under the solar power spectrum (AM1.5). The achieved results due to the effect of DLARC are compared for Si and GaAs solar cells. From these analyses, it is concluded that MgF2/ZnSe is an appropriate DLARC for the range of wavelengths 400–800 nm at 10°–30° angles of incidence in TM mode for tuning the optical and electrical properties of Si and GaAs substrates for terrestrial applications.

Effects of bending stress on structural and electrical properties of flexible CZTSSe thin film solar cells

Effects of bending stress on structural and electrical properties of flexible CZTSSe thin film solar cells

Optimization of LED-Based Solar Simulators for Cadmium Telluride and Microcrystalline Silicon Solar Cells

Solar simulators are instruments used for controllable measurements of the properties of solar cells in indoor environments. The purpose of this paper is to examine the peculiarities of the photoresponses of CdTe/CdSeTe and microcrystalline Si solar cells and to reveal the pathways to reduction of spectrum mismatch effects when using light-emitting diode (LED)-based or hybrid LED and halogen lamp-based solar simulators of an A+-class spectrum with a small number of sources. While only four different LED types are needed to achieve an A+-class spectrum under updated IEC 60904-9:2020 standard requirements, as demonstrated by our results, additional ultraviolet LEDs are necessary to reduce the spectrum mismatch. For hybrid solar simulator configurations, the combination of cool white LED arrays and halogen emitters can serve as a main light source. Optimized for both solar cell types, hybrid simulators have a lower spectral deviation and better spectrum coverage compared to LED-only simulators with the same number of distinct source types. In addition, our results predict lower spectral mismatch errors for optimized simulators when compared with conventional Xe lamp-based simulators.

Implementation of various colors in Cu(In,Ga)Se2 thin-film solar cells by diffractive nanostructures

With the increasing use of building-integrated photovoltaic technology, it has become necessary for solar panels to blend in with their surroundings. Diffractive nanostructures can be used to reduce optical losses and create colorful solar cells. To make colors on Cu(In,Ga)Se2 (CIGS) thin-film solar cells, we fabricated diffractive nanostructures by using nanoscale imprinting and transfer lithography methods. And we investigated how the material types and pattern shapes of the nanostructures influence the optical properties of solar cells, such as the short-circuit current density (JSC), coordination of color appearance, and color quality. We used two types of pillars and grating nanostructures of SiO2 and TiO2 layers on CIGS thin-film solar cells to produce various colors. The SiO2 demonstrated an increase in JSC without significant loss of color quality compared to TiO2. By utilizing a hexagonally arrayed pillar pattern, colors are observed at various angles on an axis different from the incident light, unlike colors observed only at a single angle in the grating structure. The nanoimprinting lithography process allowed us to produce high-quality nanostructures on both rigid glass and flexible stainless-steel substrates.

Dependence of deposition bath temperature for p-electrodeposited-Cu2O onto n-TiO2/ZnO bilayer thin films

The synthesis of semiconductor materials is crucial to produce the best properties of heterojunction thin films solar cell. Titanium dioxide (TiO2) is coupled with zinc oxide (ZnO) to promote high transmittance due to low utilization of the solar spectrum. In this project, p-Cu2O as absorbing layer was deposited onto n-TiO2/ZnO bilayer thin film which acts as window layer in order to complete the device. Several bath temperatures of 30, 40, 50 and 60 °C were manipulated during Linear Sweep Voltammetry (LSV) measurement and electrodeposition process for p-Cu2O thin film. The LSV measurement was employed to determine the potential value and electrochemical properties of p-Cu2O thin film. Based on findings, the suitable deposition potential chosen is − 0.4 V vs Ag/AgCl. The p-Cu2O thin film deposited at bath temperature of 40 °C exhibited the highest diffraction peak intensity in the (111)-preferred plane orientation showing high crystallinity. The surface morphology of homogeneous and well-defined triangular shape with thickness of 4.93μm was observed. The estimated bandgap energy of 1.92 eV acquired indicated to p-Cu2O thin film. The n-TiO2/ZnO bilayer/p-Cu2O heterojunction thin film was successfully fabricated and showed significant electrical rectification properties. Here in, bath temperature influenced to the enhancement of heterointerface growth development in several properties.