CZTS Research Articles

Design and simulation of highly efficient CZTS/CZTSSe based thin-film solar cell

Thin-film solar cells are a substitute for more common crystalline silicon solar cells, which consist of thin semiconductor layers. Thin-film materials comprise direct bandgap and can absorb sunlight more efficiently than silicon. In this article, a double-absorber-based thin-film solar cell comprising CZTS/CZTSSe is designed and optimized through numerical simulation. The proposed solar cell structure consists of a transparent window layer made of aluminum-doped zinc oxide, followed by an intrinsic zinc oxide layer, an n-type cadmium sulfide layer, and a p-type combined absorber layer of copper zinc tin sulfide (Cu2ZnSnS4) (CZTS) and copper zinc tin sulfur-selenium alloy (Cu2ZnSn(S,Se4)) (CZTSSe). The structure is further optimized by introducing two interfacial layers between CZTSSe/CZTS and CZTS/CdS. The highest conversion efficiency is achieved by adjusting the thicknesses of the layers, the doping densities in different layers, and the defect densities in the two absorber layers. The optimized model, with a total thickness of 2.01 μm, demonstrates an open-circuit voltage (Voc) of 0.7669 V, a short-circuit current (Jsc) of 48.57740 mA/cm2, a fill factor (FF) of 70.61%, and efficiency (η) of 26.31%. These results suggest that CZTS is a promising candidate for replacing other thin-film photovoltaic materials, such as CdTe. The proposed double-absorber thin-film solar cell optimizes doping concentration, thickness, and defect density to enhance performance metrics and efficiency while utilizing non-toxic materials to promote cost-effective, environmentally friendly energy solutions.

Thermal transport in metal halide perovskites and other third-generation photovoltaic materials

Third-generation photovoltaic materials, including metal halide perovskites (MHPs), colloidal quantum dots (QDs), copper zinc tin sulfide (CZTS), and organic semiconductors, among others, have become attractive in the past two decades. Unlike their first- and second-generation counterparts, these advanced materials boast properties beyond mere photovoltaic performance, such as mechanical flexibility, light weight, and cost-effectiveness. Meanwhile, these materials possess more intricate crystalline structures that aid in understanding and predicting their transport properties. In particular, the distinctive phonon dispersions in MHPs, the layered architecture in quasi-two-dimensional (2D) perovskites, the strong quantum confinement in QDs, and the complex crystal structures interspersed with abundant disorders in quaternary CZTS result in unique and sometimes anomalous thermal transport behaviors. Concurrently, the criticality of thermal management in applications such as photovoltaics, thermoelectrics, light emitting diodes, and photodetection devices has received increased recognition, considering that many of these third-generation photovoltaic materials are not good thermal conductors. Effective thermal management necessitates precise measurement, advanced modeling, and a profound understanding and interpretation of thermal transport properties in these novel materials. In this review, we provide a comprehensive summary of various techniques for measuring thermal transport properties of these materials and discuss the ultralow thermal conductivities of three-dimensional (3D) MHPs, superlattice-like thermal transport in 2D perovskites, and novel thermal transport characteristics inherent in QDs and CZTS. By collecting and comparing the literature-reported results, we offer a thorough discussion on the thermal transport phenomenon in these materials. The collective understanding from the literature in this area, as reviewed in this article, can provide guidance for improving thermal management across a wide spectrum of applications extending beyond photovoltaics.

Hydrogen and Oxygen evolution reaction analysis of pristine and microwave-irradiated CZTS nanoparticles

In this present work, CZTS (Copper Zinc Tin Sulfide) nanoparticles were prepared via simple chemical route. The sample was irradiated with microwave-radiation and then hydrogen-production analysis was done. The structural and optical parameters of pristine and irradiated-samples were studied using characterization techniques such as XRD, UV–Vis and XPS. The irradiated-sample showed good efficiency in hydrogen evolution than the pristine-sample.

Investigation of sol-gel derived CZTS thin film based solar cell: Experimental and theoretical approach

The successful deposition of eco-friendly Copper Zinc Tin Sulphide (CZTS) thin films on soda lime glass substrates by spin-coating technique has been investigated. The films were deposited by varying the Cu/(Zn + Sn) ratio, ranging from 0.25 to 1.25. The deposited films exhibited a polycrystalline structure with a single kesterite phase with a preferred orientation along the (112) plane. The size of the crystallites was found to be in the range of 14 to 16.6 nm. The higher absorbance of the films was found to be near infrared, with a band gap of 1.56 to 1.72 eV. Higher carrier concentrations of CZTS films were observed with p-type conductivity. The efficiency of CZTS solar cells was studied using the simulator SCAPS-1D. Theoretical graphs of J-V efficiency were also drawn and calculated theoretically.

Efficiency enhancement of CZTS solar cell with WO3 buffer layer using CZTSe BSF layer

Non-toxic, low-cost, and bandgap-direct material Copper Zinc Tin Sulphide (CZTS) is a promising candidate thin film solar cell. As the effort to improve the efficiency of the CZTS solar cell, this work chooses an environmentally friendly tungsten oxide (WO3) as the buffer layer due to its high bandgap and excellent electrical conductivity. Furthermore, Cu2ZnSnSe4 (CZTSe) is employed as the back surface field (BSF) layer which is sandwiched between the absorber layer and the back contact layer. A new structure Pt/CZTSe/CZTS/WO3/ZnO is proposed and a comparative study is done between structures with and without BSF layer. The research investigates how the layer thickness, operating temperature, different back contact layer, acceptors, and defects in BSF layer affect the performance of CZTS solar cell using the solar cell capacitance simulator (SCAP-1D) simulation software. Efficiency of CZTS solar cell with WO3 is greatly improved with efficiency as high as 29.37 % for the proposed new structure.

Simulation Study for Nb‐Doped MoS2${\rm MoS}_2$ Layer in CZTS‐Based Solar Cells: Assessment of Challenges

AbstractThe unintentional formation of a layer as a reaction product between the copper zinc tin sulfide (CZTS) thin film and the Mo back contact reduces cell efficiency due to high sheet resistance and carrier recombination. To limit the formation of , an intentionally grown p‐type Nb‐doped layer can serve as an effective hole transport layer. This study presents a detailed study and calculations for CZTS/Mo‐based solar cells, providing guidelines for calibration. Optimizing cell efficiency is influenced by various interconnected factors in Nb‐doped . While a high carrier concentration in Nb‐doped is assumed to enhance efficiency, other parameters such as band state, optical absorption, and carrier mobility also play crucial roles and can limit cell performance. This simulation study evaluated the effect of Nb‐doped layers with different carrier concentrations to determine the optimal conditions for this p‐type layer. This work reveals that a very thin layer (13 nm) of Nb‐doped p‐type can achieve a maximum efficiency of 11.34% (with = 1.5 ) and that for an Nb‐doped p‐type 62 nm is 15.82 % (with = 4.03 ).

C60/CZTS Junction Combination to Improve the Efficiency of CZTS-Based Heterostructure Solar Cells: A Numerical Approach

This work presents a copper zinc tin sulfide (CZTS)-based solar cell structure (AI/ITO/C60/CZTS/SnS/Pt) with C60 as a buffer layer, developed using the SCAPS-1D simulator by optimizing each parameter to calculate the output. Optimizing the parameters, the acceptor concentration and thickness were altered from 6.0 × 1015 cm−3 to 6.0 × 1018 cm−3 and 1500 nm to 3000 nm, respectively. Although, in this simulator, we can tune the value for the acceptor concentration to 6.0 × 1022, higher doping might present an issue regarding adjustment in the physical experiment. Thus, tunable parameters need to be chosen according to the reliability of the experimental work. The defect density varied from 1.0 × 1014 cm−3 to 1.0 × 1017 cm−3 and the auger hole/electron capture coefficient was determined to be 1.0 × 10−26 cm6 s−1 for the maintenance of the minorities in theoretical to quasi-proper experimental measurements. Although the temperature was intended to be kept near room temperature, this parameter was varied from 290 K to 475 K to investigate the effects of the temperature on this cell. The optimization of the proposed structure resulted in a final acceptor concentration of 6.0 × 1018 cm−3 and a thickness of 3000 nm at a defect density of 1.0 × 1015 cm−3, which will help to satisfy the desired experimental performance. Satisfactory outcomes (VOC = 1.24 V, JSC = 27.03 mA/cm2, FF = 89.96%, η = 30.18%) were found compared to the previous analysis.

Ecodesign of Kesterite Nanoparticles for Thin Film Photovoltaics at Laboratory Scale.

This manuscript investigates the efficient synthesis of copper zinc tin sulfide (CZTS) nanoparticles for CZTS thin film solar cell applications with a primary focus on environmental sustainability. Underpinning the investigation is an initial life-cycle assessment (LCA) analysis. This LCA analysis is conducted to evaluate the environmental impact of different synthesis volumes, providing crucial insights into the sustainability of the synthesis process by considering the flows of material and energy associated with the process. Life-cycle assessment results demonstrate that significant reductions to the environmental impact can be made by increasing the synthesis volume of CZTS nanoparticle ink. Using a 5-fold increase in volume can reduce all 11 investigated environmental impacts by up to 35.6%, six of these impacts demonstrating reductions >10% and the amount of global warming potential is reduced by 21.4%. Motivated by the LCA results, COMSOL simulations are employed to understand the fluid flow patterns in large-scale fabrication. Various sizes and speeds of stirrer bars are investigated in these simulations, and it is determined that a 50 mm stir bar at 200 rpm represents the optimal configuration for the synthesis process in a 500 mL flask. Subsequently, large-batch CZTS nanoparticle inks are synthesized using these parameters and compared to small-batch samples. The light absorbers are characterized using Raman spectroscopy and X-ray diffraction, confirming favorable properties with close-to-ideal elemental ratios in large-batch synthesis. Finally, solar cell devices fabricated utilizing CZTSSe absorbers from the large volume synthesis process demonstrate comparable performance to those fabricated using small-batch synthesis, with uniform power conversion efficiencies of around 5% across the substrate. This study highlights the potential of large-volume CZTS nanoparticle synthesis for efficient and environmentally friendly CZTS solar cell fabrication, contributing to the advancement of sustainable renewable energy technologies.

Improving CZTS/ZTO solar cell efficiency with inorganic BSF layers

Copper zinc tin sulfide (CZTS) thin-film solar cells have garnered significant attention in the solar energy sector. This study aims to enhance the performance of CZTS solar cells by replacing the conventional, toxic CdS buffer layer with Zn1−xSnxO (ZTO) for x = 0.2. Utilizing the one-dimensional solar cell capacitance simulator (SCAPS-1D) and informed by experimental data on the physical properties of the solar cell layers, we investigated the effects of thickness, doping density, and defect density of the CZTS absorber layer on the cell’s performance. Initially, an efficiency of 14.76% was achieved. To improve this efficiency, an inorganic back surface field (BSF) layer was incorporated to mitigate charge carrier recombination at the absorber/back contact metal interface. Various materials, including CuO, Cu2O , Mo S2 and Mo Se2 , were evaluated as potential BSF layers. Comparative analysis indicated that the inclusion of the BSF layer significantly enhances the solar cell efficiency, achieving up to 27% with Cu2O as the BSF material. Furthermore, the study included an analysis of temperature effects and parasitic resistances to comprehensively assess the solar cell’s performance.

Effects of Al2O3 Rear Interface Passivation on the Performance of Bifacial Kesterite‐Based Solar Cells with Fluorine‐Doped Tin Dioxide Back Contact

Herein, ultrathin Al2O3 is investigated as a rear interface passivation layer for kesterite solar cells with F:SnO2 (FTO) back contact for potential performance improvement. On the passivation layer, a thin Mo layer is deposited to improve the FTO's ohmicity. Further, NaF is evaporated on the copper zinc tin sulfide (CZTS) precursors to create openings at the passivation layer and achieve Na‐induced benefits in the absorber. The CZTS absorbers deposited directly on the Al2O3‐coated FTO peel off, while those with Mo interlayer do not. For pure sulfide kesterite devices, the Al2O3 layer reduces the short‐circuit current density (JSC), resulting in poor device efficiency. On the other hand, significantly higher JSC is realized for mixed sulfide and selenide kesterite devices with Al2O3 passivation layer, with the current density–voltage curve suggesting a reduced barrier height at the rear interface. As a result, the efficiency is improved from 1.5% for devices without Al2O3 to 4.6% for those with Al2O3. Likewise, improved external quantum efficiency response is observed in the devices with passivation layer for backside and frontside illumination. Therefore, contribution of Al2O3 passivation layer to the performance of kesterite‐based solar cells is evident from the results of this study.

Kesterite Films Processed with Organic Solvents: Unveiling the Impact of Carbon‐Rich Fine‐Grain‐Layer Formation on Solar‐Cell Performance

Solution‐processed kesterite (copper zinc tin sulfide [CZTS]) solar cells attract significant attention owing to their low cost, ease of large‐scale production, and earth‐abundant elemental composition, which make these devices promising to fulfill the ever‐increasing demand of the photovoltaic (PV) industry. Compared to the performances of expensive vacuum‐based techniques, colloidal nanocrystal kesterite solar cells garner substantial interest due to their economical and rapid processing. Led by the hot‐injection method, organic solvent‐based techniques are widely adopted to realize CZTS nanocrystal inks. With organic solvents, ligand‐stabilized nanoparticles are formed leading to dispersive and homogenous kesterite inks. However, the presence of carbon‐rich ligands around the nanocrystal surface often leads to the formation of a fine‐grain layer that is rich in carbon content. The organic ligands decompose into amorphous carbon residues during a high‐temperature annealing process and hinder the grain growth process. The carbon‐rich fine‐grain (CRFG) layer generally poses a negative influence on the PV performance of the kesterite solar cell; however, few reports maintain their disposition about CRFG as innocuous. In this review study, a detailed discussion on CRFG is presented, aiming to understand the insights about its formation and impact on the device's performance.

Process of solvothermal CZTS nanomaterial for application of solar cell

Sustainable technological development is always associated with usage of energy. Development is directly proportional to utilization of energy. Therefore, energy crisis is one of the crucial issue encounters to mankind during their growth and development of technology. Recent years, researchers comprising many materials like Copper Indium Selenide, Copper Indium Sulfide, Copper Indium Gallium Selenide, Cadmium Telluride and many more. But these all materials are accompanying high cost, lack of abundant sources and toxicity. Hence, thinking about low cost featuring and nontoxicity to overcome energy crisis, Copper Zinc Tin Sulfide (CZTS) is considered as one of the best alternatives in semiconductor solar cell. There are various methods to synthesized CZTS materials, which requires high-cost set ups and equipment. In this paper we have used low-cost synthesis process. CZTS nanomaterials were synthesized in non-aqueous solution with the help of solvothermal method. Synthesis of CZTS nanomaterial was carried out by using Teflon Lined Autoclave in furnace. Further thin films of CZTS material. Further, films were characterized scientifically with the help of UV–VIS spectroscopy, X-ray diffraction, Scanning electron microscopy and potentiometer. CZTS material further annealed at 400 °C for 10 min with which we have observed annealing effect on it. Due to annealing, properties like crystallinity, absorptions and morphology were improved which may be benefitted for progress of efficiency solar cells.

Efficiency enhancement above 31 % of Sb2Se3 solar cells with optimizing various BSF layer

Recent advancements in solar technology have increased the acceptance of antimony selenide (Sb2Se3) due to its advantageous properties. This study aims to enhance the performance of the Sb2Se3 structure by using tungsten disulfide (WS2) as the window layer and copper zinc tin selenide (CZTSe) as the back surface field (BSF) layer, utilizing SCAPS-1D (solar cell and capacitance simulator). An initial investigation of seven potential BSF layers identified CZTSe as the best choice for improving power conversion efficiency (PCE). By carefully simulating various parameters, including the thicknesses of the absorber and window layers, donor and acceptor densities, defect density, shunt resistance, and series resistance, significant performance improvements were achieved. Without the BSF layer, the cell showed a PCE of 28.20 % along with specific values for short circuit current density (JSC), open-circuit voltage (VOC), and fill factor (FF). The addition of the BSF layer increased the PCE to 31.52 %, along with enhancements in JSC, VOC, and FF. These results highlight the potential of this approach for developing high-performance Sb2Se3 based solar cells, surpassing conventional designs.

An Investigation on Structural, Morphological, Optical, and Electrical Properties of Copper Zinc Tin Sulfide (CZTS) Thin Films Prepared by SILAR Method

An Investigation on Structural, Morphological, Optical, and Electrical Properties of Copper Zinc Tin Sulfide (CZTS) Thin Films Prepared by SILAR Method

Enhancing efficiency of Sb2Se3 solar cell through optimized optical and electrical properties with Bi-layer absorber

In this study, an innovative solar cell utilizing antimony selenide (Sb2Se3) as a base material and incorporating a dual absorber layer is comprehensively examined using the Solar Cell Capacitance Simulator (SCAPS-1D) tool. The aim is to assess the performance of the solar cell with different absorber layers in combination with Sb2Se3. Results demonstrate that the solar cell employing an organic CH3NH3SnI3 absorber layer alongside Sb2Se3 achieves superior efficiency compared to one with an inorganic CZTS absorber layer. The two absorber layers investigated are the inorganic Copper Zinc Tin Sulfide (CZTS) and the organic methylammonium tin iodide (CH3NH3SnI3 The dual absorber layer configuration proves advantageous by enhancing light absorption. The solar cell architecture comprises ZnO/i-ZnO/Sb2Se3/CZTS or CH3NH3SnI3/NiO layers, resulting in an improved efficiency of up to 36.70%. Throughout the analysis, parameters such as concentration, band gap, thickness, and temperature are systematically adjusted to evaluate the behavior of this unique solar cell structure. The findings from the study indicate a noticeable enhancement in the performance of Sb2Se3 solar cells when employing the bilayer absorber structure comprising Sb2Se3 and CH3NH3SnI3.

Facile hydrothermal synthesis of a multifunctional copper zinc tin sulfide (CZTS) nanoparticle-coated sepiolite fiber composite: structural characterization and photocatalytic properties

This work presents a facile hydrothermal synthesis method for fabricating a multifunctional composite of copper zinc tin sulfide (CZTS) nanoparticles coated onto sepiolite fibers. Morphological analysis confirms the firm attachment of approximately 10 nm CZTS nanoparticles onto the sepiolite surface. Elemental analysis verifies the presence of constituent elements from both CZTS and sepiolite, with a slight deficiency in Cu and an abundance of Zn observed. The compositional formula of CZTS in the composite is estimated as Cu1.93Zn1.05Sn0.98S4.04. Notably, the material exhibits a narrow band gap of 1.5 eV, enabling effective utilization of the entire visible light spectrum, making it promising for photocatalytic applications. BET nitrogen adsorption/desorption measurements reveal a substantial surface area of approximately 85.720 m2 /g, confirming the composite’s versatility and applicability, particularly in photocatalysis and adsorption processes. Additionally, X-ray diffraction analysis indicates reflections consistent with the crystal structures of kasterite CZTS and sepiolite, further confirming the composite’s composition. The multifunctional CZTS/Sepiolite composite demonstrates exceptional potential for simultaneous photocatalytic degradation and adsorption of organic pollutants, presenting a promising avenue for sustainable water treatment applications.

Ion implantation induced p-type conductivity in FeS2 thin film

In pursuing sustainable energy solutions, thin-film solar cells based on the Copper zinc tin sulfide (CZTS) absorber material have garnered significant attention due to their earth-abundant and non-toxic composition. However, the modest efficiency demonstrated by CZTS solar cells has prompted researchers to investigate novel approaches to improve their performance. An area of potential advancement entails the integration of appropriate hole transport layers (HTLs). In this simulation-based study, we focused on FeS2 as a highly promising candidate for use as an HTL in CZTS-based solar cells. FeS2, traditionally considered n-type, was tailored to achieve p-type conductivity through the negative ion implantation (O, P, and As) process. 40 keV ion beam was utilized, with three doses (105, 1010, 1015 cm−2) applied for each ion beam. We demonstrate successful p-type doping of FeS2 with a hole concentration of ∼1020 cm−3 in case of 1015 cm−2 dose, paving the way for its integration as an effective HTL within the CZTS solar cell structure.

Recent Progress and Challenges in Controlling Secondary Phases in Kesterite CZT(S/Se) Thin Films: A Critical Review

Kesterite-based copper zinc tin sulfide (CZTS) and copper zinc tin selenide (CZTSe) thin films have attracted considerable attention as promising materials for sustainable and cost-effective thin-film solar cells. However, the successful integration of these materials into photovoltaic devices is hindered by the coexistence of secondary phases, which can significantly affect device performance and stability. This review article provides a comprehensive overview of recent progress and challenges in controlling secondary phases in kesterite CZTS and CZTSe thin films. Drawing from relevant studies, we discuss state-of-the-art strategies and techniques employed to mitigate the formation of secondary phases. These include a range of deposition methods, such as electrodeposition, sol-gel, spray pyrolysis, evaporation, pulsed laser deposition, and sputtering, each presenting distinct benefits in enhancing phase purity. This study highlights the importance of employing various characterization techniques, such as X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy, for the precise identification of secondary phases in CZTS and CZTSe thin films. Furthermore, the review discusses innovative strategies and techniques aimed at mitigating the occurrence of secondary phases, including process optimization, compositional tuning, and post-deposition treatments. These approaches offer promising avenues for enhancing the purity and performance of kesterite-based thin-film solar cells. Challenges and open questions in this field are addressed, and potential future research directions are proposed. By comprehensively analyzing recent advancements, this review contributes to a deeper understanding of secondary phase-related issues in kesterite CZT(S/Se) thin films, paving the way for enhanced performance and commercial viability of thin-film solar cell technologies.

Polymorphs of Copper Zinc Tin Sulfide: Optoelectronic Properties and Detection Using Raman

Despite its growing popularity as a solar material, there is no comprehensive reference to aid with determining various polymorphs of copper zinc tin sulfide (CZTS) in the lab. Understanding the diverse electronic, optical and vibrational properties of these polymorphs is crucial to further enhance the conversion efficiency of CZTS solar cells. Here, findings are presented that suggest the effective hole mass in a monoclinic polymorph, that is likely to form along with the more commonly reported tetragonal variations, is about 10 times heavier than that of its tetragonal counterparts, thereby affecting key attributes such as carrier transport and concentration. Among tetragonal polymorphs, the so‐called primitive mixed CuAu (PMCA) arrangement is likely to undergo a direct‐indirect gap transition due to internal strains. Optical absorption between different polymorphs could also vary by up to 90% in the visible spectrum. Finally, accurate Raman footprint of each polymorph is predicted to help establish a definitive method for their detection. From a modeling perspective, Becke‐Lee‐Yang‐Parr with spin‐orbit coupling is shown to be a superior yet 100X faster alternative to hybrid functionals when applied to studying electronic structure of CZTS.

Comparative study by simulation betweentwo structures CdS/CZTS and ZnS/CZTS via SCAPS-1D software

This comparative numerical simulation study investigates the electrical characteristics of two heterojunction thin-film solar cells based on Kësterites Copper Zinc Tin Sulfide. The study compared two solar cells with different structures, Zinc Oxide ZnO/Cadmium Sulfide CdS/Kësterites CZTS/Molybdenum Mo and Zinc Oxide ZnO/Zinc Sulfide ZnS/Kësterites CZTS/Molybdenum Mo, to determine which is more efficient in achieving maximum photovoltaic efficiency. The results showed that the ZnO/ZnS/CZTS/Mo solar cell is the better option, outperforming the CdS/CZTS/Mo solar cell in terms of short-circuit current density Jsc, open-circuit voltage Voc, form factor FF, and photovoltaic efficiency η. The study also investigated the effect of doping and layer thickness of CZTS and ZnS on photovoltaic parameters. The optimized ZnS/CZTS solar cell achieved an efficiency of 16.29% for ZnS and CZTS layer thicknesses of 0.02µm and 4μm, respectively, and doping concentrations of 1018 and 1016cm-3 , respectively. Overall, this study provides valuable insights for designing more efficient solar cells and optimizing their photovoltaic efficiency using Kësterites CZTS, CdS, and ZnS materials.