Absorber Material For Solar Cells Research Articles

Influence of sulfurization temperature on grain growth in Cu2ZnSnS4 thin films synthesized for solar cell applications

Copper-zinc-tin-sulfur (CZTS) thin films, prepared through a dip-coating solution method, present a highly attractive option as absorber materials for thin-film solar cells. This is due to their affordability, environmentally friendly composition, and abundant availability of raw materials. Although films processed with hydrazine-based solutions have achieved the highest efficiency of approximately 12.6%, the toxic and carcinogenic nature of hydrazine negates these advantages. In the ongoing global research on solution-based processing methods, the size of the grains has emerged as a critical factor in the fabrication of efficient solar cells. In our study, we have successfully prepared CZTS thin films with a pure kesterite phase, characterized by large micro-sized grains, using a dip-coating process with an ethanol-based precursor solution, followed by sulfurization. We investigated how the grain size evolves with varying sulfurization temperatures. Notably, we observed that increasing the temperature led to larger and more uniform grain growth. These results underscore the potential of our approach for the straightforward production of high-quality films with sizable grains, ultimately enhancing their photosensitivity and making them a promising candidate for efficient solar cell applications.

Ultrasonic spray synthesis, photoelectric properties and photovoltaic performances of chalcogenide CaSnS3

Chalcogenide perovskites are promising lead-free, stable absorber materials for solar cells. This work reports the synthesis of orthorhombic phase pure CaSnS3 thin films by facile low temperature sulfurization of solution-processed CaSnO3 oxide precursors. Structural characterization confirms complete anion exchange to produce crystalline CaSnS3 films with vertically aligned rod-like grains. Optical studies show strong visible light absorption with direct bandgap of 1.72 eV, ideal for photovoltaics. Electrical measurements indicate p-type conductivity with hole concentration of 1.2×1017 cm-3 and mobility around 8 cm2V-1s-1 at room temperature. First-principles DFT calculations corroborate the p-type electronic structure. Prototype CaSnS3 solar cells are fabricated with TiO2 electrode, demonstrating power conversion efficiency of 2.5% under AM1.5G, open-circuit voltage of 0.55 V, short circuit current density of 11.5 mA/cm2 and fill factor of 0.62. The cells also exhibit remarkable ambient shelf stability over 6 months. The comprehensive results validate the photovoltaic potential of these earth abundant, sustainable chalcogenide perovskites synthesized via scalable low-cost solution methods. Further interface engineering can enable enhanced efficiencies.

The big bang of halide perovskites: The starting point of crystallization

Hybrid halide perovskites (HHPs) are very promising absorber materials for solar cells due to their high power conversion efficiency and the low-cost solution-based processing methods. We applied small angle X-ray scattering to MAPbI3, FAPbI3 and MAPbBr3 precursor solutions in different solvents (GBL, DMF, and mixtures) to gain a deeper understanding of the building blocks during the early stage of HHP formation. We present a core–shell model where the core is formed by [PbX6] octahedra surrounded by a shell of solvent molecules, which explains the arrangement of the precursors in solution and how the solvent and the halide influence such arrangement.Graphical

Study of defect density of copper vacancies in chalcogenide CuSbS2, CuSbSe2, CuBiS2, and CuBiSe2 heterojunction thin-film solar cells.

In the past decade, a new family of ternary chalcogenide absorber (TCA) materials MIMIIX2 (where MI = Cu, Ag, Pb; MII = Sb, Bi, In; and X = S, Se, Te) have been studied. The copper family of ternary chalcogenide CuSbS2 CuSbSe2 CuBiS2, and CuBiSe2 is an amazing absorber material for thin-film solar cells because of their suitable band gap, high absorption coefficient and inexpensive, nontoxic, environment friendly and sustainable nature. In the presented work, first time simulated defect density of copper vacancies in CuSbS2 (CAS), CuSbSe2 (CASe), CuBiS2 (CBS) and CuBiSe2 (CBSe) has based heterojunction thin-film solar cells (HJTFSCs) with buffer CdS, intrinsic i-ZnO, window ZnO: Al and back contact Mo and set the cell scheming ZnO: Al/i-ZnO/n-CdS/p-TCA/Mo using SCAPS 1D. Major focus of this paper is on the influence of copper vacancies defect density that impact on the performance of ternary chalcogenide with various parameters of solar cells, i.e. short-circuit current density (Jsc), open-circuit voltage (Voc), form factor (FF) and efficiency (η). The cell parameter set at constant temperature 300K, thickness 2.5μm, carrier density 5 × 1016cm-3, front internal transmission coefficient 1 and illumination intensity 100 mW/cm2 with AM1.5 sun light. This study clarifies the potential benefits to utilizing of ternary chalcogenide compounds as absorber material for solar cell fabrication.

Investigation of GeSe Photovoltaic Device Performance via 1-Dimensional Computational Modelling

Germanium selenide (GeSe) is a potential absorber material for thin film solar cells. However, many physical, electronic parameters and practical defect configurations that result in different effects on the performance of GeSe solar cells are not fully understood. In this study, a baseline of a GeSe thin film solar cell was designed and simulated using SCAPS-1D simulator. The physical and electronic parameters of the absorber layer is varied to investigate their effect on the performance of the solar cell. The simulation uses absorption files extracted from Xue et al. 2016 and the SCAPS-1D absorption model. Practical defect configurations are also introduced in GeSe thin film solar cells to optimize solar cell performance. Simulation results show that baseline GeSe solar cells had obtained Voc 0.62 V, Jsc 39.52 mA/cm<sup>2</sup>, FF 79.34 and ƞ 19.48%. Simulation using the SCAPS-1D absorption model achieved a more accurate JSC contour graph compared to simulation using absorption files extracted from Xue et al. 2016. The highest efficiency of 26.13% was achieved at 1.40 eV bandgap, 4.27 eV electron affinity, 10 cm2/Vs hole mobility, 1E+18 1/cm<sup>3</sup> hole concentration and 2000 nm GeSe layer thickness. For bulk defect, an increase in defect concentrations or capture cross section hole and electron (σ) reduce efficiency. For interfacial defect GeSe/CdS, total density of 1E+12 1/cm<sup>2</sup> with σ of 1E-13 cm<sup>2</sup>, total density of 1E+18 1/cm2 with σ of 1E-19 cm<sup>2</sup>, total density of 1E+16 1/cm<sup>2</sup> and 1E+18 1/cm<sup>2</sup> with σ of 1E-16 cm<sup>2</sup> have critical impact to solar cell.

Fabrication and adapting the optical, and dielectric performance of PVC/ MnFe2O4/ZnMn2O4 nanocomposite films for optoelectronic applications

The current study focuses on the fabrication of hybrid flexible polymers composed of MnFe2O4/ZnMn2O4 nanocomposites doped polyvinyl chloride (PVC). The doped polymers show great potential for utilization in a wide range of optoelectronics applications. PVC/(1-x)MnFe2O4/xZnMn2O4 were made using the casting and sol gel processes. The effect of (1-x)MnFe2O4/xZnMn2O4 nanocomposite samples on the optical parameters of PVC polymer has been explored using ultraviolet–visible diffused reflectance measurements. Doped polymers might be useful as protective barriers against ultraviolet radiation of various wavelengths (UVA, UVB, UVC) and as excellent absorber materials for solar cells. The direct and indirect bandgaps (Eg) of PVC are 4.26 and 4.08 eV. The direct/indirect optical band gap lowered to their lowest 3.97/3.45 eV as the PVC doped with nanofillers contained 50 %/80 % ZnMn2O4, respectively. Different models were used to extracted the refractive index (n) of different polymers based on the obtained optical band gaps (direct/indirect). Doped polymers containing 50 and 80 % ZnMn2O4 had the highest n values using direct and indirect Eg values, respectively. The n value (obtained from the direct optical bandgap energy) of PVC increased from 2.209 to the maximum value (2.262) as x = 0.5. The n value (obtained from the indirect optical bandgap energy) of PVC increased from 2.349 to the maximum value (2.367) as x = 0.8. All linear and nonlinear optical parameters of PVC polymer were improved as it doped with the nanocomposite fillers. The fluorescence (FL) intensity of PVC was reduced as it was doped with (1-x)MnFe2O4/xZnMn2O4 and this intensity reduced as the content of ZnMn2O4. The standard (CIE) color space chromaticity diagram was used to analysis the FL spectra for different samples. The effect of nanocomposite samples on the AC conductivity, dielectric constants and electric modulus of the PVC was studied. At 1 kHz, the dielectric constant of PVC was increased from 11.745 to 12.906 and 12.096 for polymers with x = 0 and x = 0.2, respectively. The enhanced optical and dielectric properties of the PVC/(1-x)MnFe2O4/xZnMn2O4 polymers nanocomposites suggest that these materials are suitable for smart electronic devices.

Studies on the performance of FASnI3:Zn2+-based lead-free perovskite solar cells: A numerical simulation

The search of stable, lead-free absorber material for perovskite solar cells (PSC) resulted in many alternatives, particularly, zinc (Zn) doped formamidinium tin iodide (FASnI3). This work facilitates in investigating the behavior of four different Zn doping ratios 0 %, 2 %, 5 %, and 10 % (say Zn-0, Zn-2, Zn-5, and Zn-10) on the performance of FTO/PCBM/FASnI3:Zn2+/MoOx/Au solar cell structure. A precise evaluation on the impact of the four various Zn doping ratios in the mentioned solar structure in terms of thickness of perovskite absorber layer, hole transport layer, and electron transport layer were executed. The investigation through numerical study further deals with the role of interfacial defect density and capture cross-section of charge carriers on the performance of suggested PSCs with varying Zn doping ratios. It is evident from the optimization results that PSC having absorber layer thickness of 400 nm yields better power conversion efficiency (PCE) of 11.49 % for Zn-5. The PCE is further improved to 13.98 % for capture cross section of 2 ×10−15 cm2. The entire work witnessed distinguishable superior behavior from FASnI3-based PSC doped with Zn ratio: Zn-5 in comparison to the PSCs doped with other Zn ratios. Furthermore, impact of the series and shunt resistances on performance parameters are also examined.

The effect of annealing and thickness on optical and electrical properties of Cs2AgBiI6 layer prepared by thermal evaporation method as an absorber material for lead-free perovskite solar cells

The effect of annealing and thickness on optical and electrical properties of Cs2AgBiI6 layer prepared by thermal evaporation method as an absorber material for lead-free perovskite solar cells

Graphene oxide-titanium oxide-polyaniline hybrid materials for high-performance dye-sensitized solar cells

A new solar cell that comprises a graphene oxide and titanium oxide nanoparticle (NP) composite with graphitized polyaniline (PANI) has been tested in polymer solar cells (PSCs). In this study, a series of conjugated polymers were synthesized and evaluated as the absorber and hole-transport layer materials in organic solar cells, demonstrating the significant impact of the chemical structure of the polymers on solar cell performance. The incorporation of graphene oxide (GOX) and titanium oxide TiO2 NP in conjugated polymers, particularly when graphitized within the PANI layer, led to improved open-circuit voltages compared to structurally similar polymers without NP. The morphology of the composite films was analyzed and related to the photovoltaic performance of polymers synthesized with polyaniline PANI-base and PANI-salt. Optimal NP addition in PANI-salt, PANI-base, PANI-base-TiO2, and PANI-base-GOX resulted in open-circuit voltages and efficiencies of 433 mV and 3.67%, 250 mV and 0.595%, 310 mV and 1.358%, and 520 mV and 2.366%, respectively. This study underscores the importance of polymer film uniformity in the performance of PSCs, with the highest efficiency obtained using a conjugated polymer with the best PANI-salt and PANI-base-GOX films. The research sheds light on the relationship between polymer structure and device photovoltaic performance, which is crucial for the design of new polymeric materials for efficient use and stable OSCs and PSCs.

Formamidinium Lead Iodide-Based Inverted Perovskite Solar Cells with Efficiency over 25 % Enabled by An Amphiphilic Molecular Hole-Transporter.

Formamidinium lead iodide (FAPbI3) represents an optimal absorber material in perovskite solar cells (PSCs), while the application of FAPbI3 in inverted-structured PSCs has yet to be successful, mainly owing to its inferior film-forming on hydrophobic or defective hole-transporting substrates. Herein, we report a substantial improvement of FAPbI3-based inverted PSCs, which is realized by a multifunctional amphiphilic molecular hole-transporter, (2-(4-(10H-phenothiazin-10-yl)phenyl)-1-cyanovinyl)phosphonic acid (PTZ-CPA). The phenothiazine (PTZ) based PTZ-CPA, carrying a cyanovinyl phosphonic acid (CPA) group, forms a superwetting hole-selective underlayer that enables facile deposition of high-quality FAPbI3 thin films. Compared to a previously established carbazole-based hole-selective material (2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl)phosphonic acid (MeO-2PACz), the crystallinity of FAPbI3 is enhanced and the electronic defects are passivated by the PTZ-CPA more effectively, resulting in remarkable increases in photoluminescence quantum yield (four-fold) and Shockley-Read-Hall lifetime (eight-fold). Moreover, the PTZ-CPA shows a larger molecular dipole moment and improved energy level alignment with FAPbI3, benefiting the interfacial hole-collection. Consequently, FAPbI3-based inverted PSCs achieve an unprecedented efficiency of 25.35 % under simulated air mass 1.5 (AM1.5) sunlight. The PTZ-CPA based device shows commendable long-term stability, maintaining over 90 % of its initial efficiency after continuous operation at 40 °C for 2000 hours.

Formamidinium Lead Iodide‐Based Inverted Perovskite Solar Cells with Efficiency over 25 % Enabled by An Amphiphilic Molecular Hole‐Transporter

AbstractFormamidinium lead iodide (FAPbI3) represents an optimal absorber material in perovskite solar cells (PSCs), while the application of FAPbI3 in inverted‐structured PSCs has yet to be successful, mainly owing to its inferior film‐forming on hydrophobic or defective hole‐transporting substrates. Herein, we report a substantial improvement of FAPbI3‐based inverted PSCs, which is realized by a multifunctional amphiphilic molecular hole‐transporter, (2‐(4‐(10H‐phenothiazin‐10‐yl)phenyl)‐1‐cyanovinyl)phosphonic acid (PTZ−CPA). The phenothiazine (PTZ) based PTZ−CPA, carrying a cyanovinyl phosphonic acid (CPA) group, forms a superwetting hole‐selective underlayer that enables facile deposition of high‐quality FAPbI3 thin films. Compared to a previously established carbazole‐based hole‐selective material (2‐(3,6‐dimethoxy‐9H‐carbazol‐9‐yl)ethyl)phosphonic acid (MeO−2PACz), the crystallinity of FAPbI3 is enhanced and the electronic defects are passivated by the PTZ−CPA more effectively, resulting in remarkable increases in photoluminescence quantum yield (four‐fold) and Shockley‐Read‐Hall lifetime (eight‐fold). Moreover, the PTZ−CPA shows a larger molecular dipole moment and improved energy level alignment with FAPbI3, benefiting the interfacial hole‐collection. Consequently, FAPbI3‐based inverted PSCs achieve an unprecedented efficiency of 25.35 % under simulated air mass 1.5 (AM1.5) sunlight. The PTZ−CPA based device shows commendable long‐term stability, maintaining over 90 % of its initial efficiency after continuous operation at 40 °C for 2000 hours.

Investigating inorganic perovskite as absorber materials in perovskite solar cells: machine learning analysis and optimization

This work investigates the potential of inorganic perovskites AgBiSCl2 and Al2Cu2Bi2S3Cl8 as absorber layers in perovskite solar cells, followed by the application of supervised machine learning models. Extensive exploration and optimization of device architectures FTO/SnO2/AgBiSCl2/Spiro-OMeTAD/Au and FTO/SnO2/Al2Cu2Bi2S3Cl8/Spiro-OMeTAD/Au are conducted, involving variations in absorber layer thickness (d), bulk defect density (Nt), and carrier mobility (μ n,p). The AgBiSCl2-based device achieves an optimized conversion efficiency of 10.06%, while the Al2Cu2Bi2S3Cl8-based device achieves 12.27%. To train different machine learning models, 1600 datasets are collected for each device, and Neural Networks (NN), Random Forests (RF), and XGBoost (XGB) models are employed. The performance parameters, evaluated using mean squared error (MSE) and high R-squared (R2) values, demonstrate that XGB performs the best, achieving an MSE of 0.210 and R2 of 97.1% for AgBiSCl2 and 0.671 and 90.6% for Al2Cu2Bi2S3Cl8. Additionally, the impact of each variable (d, Nt, and μ n,p) on the output is analyzed using Shapley Additive Explanations (SHAP) plots for each model. The results presented in this study pave the way for the advancement of perovskite material-based solar cells without relying on complex optoelectronic semiconducting equations and device simulators.

Numerical simulation of Cu2Te based thin film solar cell with Cu2O HTL for high efficiency

Copper telluride (Cu2Te) is an attractive semiconductor absorber material for thin film solar cells due to its excellent opto-electronic properties. However, the maximum experimental conversion efficiency of the Cu2Te thin film solar cell remains at about 6%. In the present study, the cuprous oxide (Cu2O) material as the hole transport layer (HTL) has been proposed in the Cu2Te based thin film solar cell. The purpose of this work is to enhance the device performance by inserting widely available Cu2O material as HTL into the basic heterojunction structure. The effects of several material parameters such as thickness, carrier concentration, defect density and back contact metal work function on the device performance of the proposed Cu2Te thin film solar cell consisting of FTO/WS2/Cu2Te/Cu2O/metal have been studied and numerical investigated using the wxAMPS program. Optimized conversion efficiency of the proposed Cu2Te thin film solar cell with Au as back contact metal has been obtained to be 30.32%. These results reveal that the Cu2O material as HTL can be employed to fabricate low cost and highly efficient Cu2Te thin film solar cells.

Cation exchange synthesis of AgBiS2 quantum dots for highly efficient solar cells.

Silver bismuth sulfide (AgBiS2) nanocrystals have emerged as a promising eco-friendly, low-cost solar cell absorber material. Their direct synthesis often relies on the hot-injection method, requiring the application of high temperatures and vacuum for prolonged times. Here, we demonstrate an alternative synthetic approach via a cation exchange reaction. In the first-step, bis(stearoyl)sulfide is used as an air-stable sulfur precursor for the synthesis of small, monodisperse Ag2S nanocrystals at room-temperature. In a second step, bismuth cations are incorporated into the nanocrystal lattice to form ternary AgBiS2 nanocrystals, without altering their size and shape. When implemented into photovoltaic devices, AgBiS2 nanocrystals obtained by cation exchange reach power conversion efficiencies of up to 7.35%, demonstrating the efficacy of the new synthetic approach for the formation of high-quality, ternary semiconducting nanocrystals.

Boosting efficiency above 30 % of novel inorganic Ba3SbI3 perovskite solar cells with potential ZnS electron transport layer (ETL)

The inorganic Ba3SbI3 perovskite has emerged as a promising, stable absorber material for efficient and cost-effective solar cells, owing to its intriguing compositional, structural, electrical, and optical properties. This study delves into the potential of Iodide-based Ba3SbI3 perovskites, known for their relative stability, as absorbers in conjunction with a ZnS electron transport layer (ETL) to create a high-performance solar cell heterostructure. Using the SCAPS-1D simulator, we first estimate the absorption spectrum and bandgap of the Ba3SbI3 absorber layer through density functional theory (DFT). This obtained spectrum serves as a crucial input for device simulation. We further optimize the work function of the rear electrode to enhance the photovoltaic (PV) performance of the ZnS/Ba3SbI3 heterostructure solar cell. Various parameters including doping density, absorber thickness, and bulk/interface defect density are carefully considered. Additionally, we investigated generation and recombination rates, current density-voltage (J-V) characteristics, and corresponding quantum efficiency (QE). Under optimized conditions, our study achieves a remarkable maximum power conversion efficiency (PCE) of 30.49 %, accompanied by a photocurrent density (JSC) of 54.63 mA/cm2, fill factor (FF) of 83.75 %, and open circuit voltage (VOC) of 0.67 V in the ITO/ZnS/Ba3SbI3/Ni structure. This comprehensive analysis offers valuable insights and methodologies for the experimental design of high-performance and stable photovoltaic devices based on Ba3SbI3 perovskite.

Synchronized B-site alloying for high-efficiency inorganic tin–lead perovskite solar cells

Inorganic tin–lead perovskites with low bandgap (1.2–1.4 eV) are desired absorber materials for solar cells owing to their ideal bandgap and compositional stability. However, such tin–lead perovskites are currently subject to inferior power conversion efficiency (PCE) and the origin remains unclear. Here, for the first time, we report the metal-cation-derived unsynchronized crystallization behavior of inorganic tin–lead perovskite, exemplifying by a representative composition CsPb0.7Sn0.3I3. A tin-perovskite-targeted crystallization modulation agent, 1-(4-fluorophenyl) piperazine (1-4FP), is introduced to synchronize the B-site alloying through its strong targeted bonding with SnI2, resulting in substantially enhanced film quality with better morphology and photoelectrical properties. Furthermore, first-principles molecular dynamics simulations reveal that the agent regulates the crystallization route toward the pure phase of CsPb0.7Sn0.3I3 by suppressing the preforming of tin perovskite. With our proposed approach, the best device attains PCE of 17.55%, which is record-high for inorganic tin–lead perovskite solar cells. In addition, treated devices show excellent stability with only 10% and negligible loss after being exposed to 1 sun intensity for 700 h and being stored in N2 after over 4000 h, respectively. Our findings open a new avenue of crystallization route design in inorganic tin–lead perovskites, so as to obtaining high-quality perovskite films and associated solar cells.

Critical role of post-treatment induced surface reconstruction for high performance inorganic tin-lead perovskite solar cells

Inorganic CsPb0.7Sn0.3I3 perovskites with low-bandgap (1.2 to 1.4 eV) are desired absorber materials for solar cells owing to their ideal bandgap and compositional stability. However, the performances of inorganic Pb-Sn perovskite solar cells are much lower than their Pb-based and hybrid Pb-Sn (e.g. CsPbX3 and FAMAPbSnX3) PSCs, which might be ascribed to its poor film-forming morphology and easy oxidation of Sn2+ at the surface. Here, for the first time, a combined 1-(4-fluorophenyl) piperazine (1-4FP) additive and 1-4FP post-treatment strategy was adopted to obtain high-quality pinhole-free films through a significant surface reconstruction. Specifically, the interaction introduced by 1-4FP post-treatment can effectively prevent the inevitable Sn2+ oxidation on perovskite surface, resulting from crosslinking neighboring perovskite grains with hydrogen bonds of amine group binding to the perovskite surface. As a result, the device treated by this combined strategy achieved a PCE of 17.19 %, which is the highest efficiency of Pb-Sn alloyed inorganic PSCs (sub-1.4 eV) reported to date. In addition, the unsealed 1-4FP-treated devices maintained their initial efficiencies of approximately 100 % after storage in a nitrogen atmosphere for 4000 h. Our findings open a new avenue to obtain high-quality inorganic Pb-Sn perovskite films and associated solar cells.

The quest for optimal photovoltaics: A theoretical exploration of quasi-one-dimensional tin based chalcogenides XSnS[formula omitted] (X=Ba, Sr)

Structural, mechanical, electronic, and optical properties of alkaline metals (Ba, Sr) tin chalcogenide were investigated by the first principles method based on density functional theory (DFT) implemented in the WEIN2K program. The study found that both materials exhibit a quasi-one-dimensional nature along the b-axis, and the optimized structure agrees with the available experimental data. Mechanical properties revealed that both materials are mechanically stable, exhibit ductility, and have significant anisotropy. BaSnS3 and SrSnS3 exhibit an indirect band gap with the values of 1.55 eV and 1.39 eV, respectively. Which is favorable for photovoltaic solar cell absorber materials. Like many ternary metal chalcogenides, XSnS3 compounds show significant anisotropy in the optical properties due to their quasi-one-dimensional structure. This work determined the degree of optical anisotropy of XSnS3 in terms of the dielectric function, refractive index, optical absorption, reflectivity, optical extinction, birefringence, and energy loss function. The results indicate that BaSnS3 and SrSnS3 materials possess notable optical anisotropy and a high absorption coefficient (α≈106 cm−1), low reflectivity and energy loss function within the visible and ultraviolet energy range. It indicates their potential for use in a range of applications, such as sensors, optoelectronics, and photovoltaic solar cell absorber materials.

SCAPS study on the effect of various hole transport layer on highly efficient 31.86% eco-friendly CZTS based solar cell

Copper Zinc Tin Sulphide (CZTS) is a propitious semiconductor for active absorber material in thin-film solar cells (SCs). Here, SC architecture comprising FTO/ZnS/CZTS/variable HTLs/Au is discussed. Fluorine-doped tin oxide (FTO) and gold (Au) are used as front and back contacts, respectively. Zinc sulphide (ZnS) is used as an active electron transport layer (ETL), while different Cu-based materials (Cu2O, CuO, CuI, and CuSCN) are used as hole transport layers (HTL). A one-dimensional solar cell capacitance simulator (SCAPS-1D) is utilized to simulate the SC structure. Among different Cu-based HTLs, Cu2O is preferred as a potential candidate for high cell performance of CZTS-based SC. The effects of various layer parameters such as thickness, doping density, and carrier concentrations, electron affinity of HTL and absorber, respectively, are also discussed. After optimization of the device, variation of operating temperature and the effect of series and shunt resistance are also taken into consideration. The optimized results of thickness and acceptor concentration (NA) of absorber material are 1.5 µm and approx. 1.0 × 1019 cm−3, respectively. In addition, the function of HTL (with and without) in the designed SC structure is also studied. Capacitance–voltage (C–V) characteristics are also discussed to get an insight of built-in potential. We have achieved cell performances viz. efficiency = 31.86%, short circuit current density = 32.05 mA/cm2, open circuit voltage = 1.19 V, and fill factor = 83.37%.

A CTL-free homo-heterojunction antimony chalcogenide solar cell: Theoretical study

Exploring antimony chalcogenide as photovoltaic (PV) absorber material for solar cell is an appealing strategy. However, the conversion efficiency (η) of antimony chalcogenide solar cells including antimony selenide (Sb2Se3), antimony sulfide (Sb2S3) and antimony sulfide–selenide (Sb2(S,Se)3) lag far behind their Shockley−Queisser limit efficiency. Generally, the device PV performance of thin film heterojunction solar cells is mainly affected by the material properties of each functional layer, as well as the device architecture and heterointerface characteristics. Herein, a novel homo-heterojunction antimony chalcogenide solar cell without any carrier transport layer (CTL) consisting of FTO/(n)Sb2Se3/(p)Sb2Se3/(p)Sb2S3/Metal has been proposed. The influence of thickness, doping concentration and bulk defect density of the functional layer materials, the interface defect density at (p)Sb2Se3/(p)Sb2S3 heterointerfaces, and back contact metal work function on device PV performance have been theoretically analyzed utilized wxAMPS software. After optimization, the proposed solar cell has an open-circuit voltage (Voc) of 0.885 V, a short-circuit current density (Jsc) of 36.14 mAcm−2, a filling factor (FF) of 84.30 %, and a η of 26.97 %. These results indicate that the novel homo-heterojunction antimony chalcogenide solar cell without any CTL have the potential to become a high-efficiency PV device.