CZTS-based Solar Cells Research Articles

The interplay between optoelectronic and magnetic properties in Co-doped Cu2ZnSnS4 for next-generation solar cell devices

Abstract A search for next-generation solar cell devices to massively actualize renewable energy is being exponentially conducted. It includes the development of Cu2ZnSnS4 (CZTS)-based solar cells, which are known as cost-effective and highly stable solar cell devices. In this present research, we develop a CZTS solar cell by adding a magnetic degree of freedom using cobalt (Co) doping. We find that the Co doping can induce modulation of the crystalline structure and bandgap of CZTS, which further influences its photovoltaic performance. The increase in the grain size of the CZTS with the addition of Co doping could further induce the reduction of detrimental grain boundaries, which benefits the photovoltaic performance of CZTS-based solar cells. Co doping also generates magnetic behavior in CZTS, which supports its magnetically controlled optoelectronic properties and thus, in turn, enhances the photovoltaic performance. We believe that this study could open up opportunities to obtain next-generation solar cell devices with excellent performances by using magnetic-field induction.

Se as hetero-nucleation seeds reinforcing intermetallic diffusion for improved electrodeposition-processed CZTS solar cells

Pure sulfide-based Cu2ZnSnS4(CZTS) stands as a competitive photovoltaic material, composted of earth-abundant, low-cost, and stable constituent elements. The stacked electrodeposition process has garnered attention owing to its facile regulation of elemental composition, and its non-vacuum, room-temperature, water-based solvent operating conditions. However, the limitation based on the stacked electrodeposition-processed CZTS primarily stems from the numerous defects and detrimental interfaces induced by the deficient intermetallic diffusion. Herein, a Se nanoparticle layer at the back interface is introduced to enhance the intermetallic diffusion, optimize the precursor morphology, and subsequently accelerate the grain growth. Comprehensive characterizations reveal Se, acting as the hetero-nucleation seeds, catalyzes Cu deposition and promotes a highly porous structure with a homogeneous elemental distribution. Consequently, high-quality CZTS with enhanced crystallinity and passivated defects is achieved, thereby promoting carrier transport and suppressing non-radiative recombination. These sequential positive effects result in a substantial improvement in short current density (Jsc) and fill factor (FF), attaining an improved efficiency. Our findings offer a promising strategy to overcome the issues of the stacked electrodeposition-processed films and highly contribute to the development of high-quality CZTS-based solar cells.

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.

MoS2 augmentation in CZTS solar cells: Detailed experimental and simulation analysis

This study investigates the optimization of CZTS-based thin-film solar cells through the incorporation of MoS2 as an interfacial layer. Using SCAPS-1D simulation software, we analyzed the effects of layer thicknesses, carrier concentrations, and defect densities on device performance. The optimized CZTS (100 nm)/ MoS2(1000 nm)/ CdS(100 nm)/ ZnO(50 nm) structure demonstrated a significant efficiency increase to 19.01 % compared to 17.03 % for the CZTS (1100 nm)/ CdS(100 nm)/ ZnO(50 nm) cell. Key improvements include enhanced charge generation, quantum efficiency, and balanced carrier transport.Materials were synthesized using microwave-assisted methods and characterized by XRD and UV–vis spectroscopy. XRD confirmed the desired crystal structures, while optical bandgaps of 1.5 eV (CZTS), 1.3 eV (MoS2), 2.4 eV (CdS), and 3.3 eV (ZnO) were determined. Practical solar cells were fabricated using spin-coating techniques, with thicknesses of CZTS (122 nm)/ MoS2 (1038 nm)/ CdS(130 nm)/ ZnO(94 nm). While showing improved performance with the MoS2 layer, efficiencies were lower than simulated values due to fabrication-related defects. The best experimental cell achieved 1.89 % efficiency, compared to 1.38 % without MoS2.This research demonstrates the potential of MoS2 as an effective interfacial layer in CZTS solar cells, providing insights into optimizing layer properties for enhanced performance. The study also highlights the challenges in translating simulated improvements to practical devices, emphasizing the need for advanced fabrication techniques to minimize defects and maximize efficiency.

Optimization of efficiency of CZTS-based solar cell through exclusive BSF layer engineering method

CZTS (copper-zinc-tin-sulfur) has recently emerged as a capable material for next-generation solar devices due to its abundance and lack of toxicity. In this study, we numerically assess the photovoltaic performance of CZTS solar cells integrated with a Back-Surface Field (BSF) layer, which is a novel approach to enhancing solar cell efficiency. We investigate the impact of various parameters, such as temperature, CZTS layer thickness, acceptor doping concentration, metal work function, and series and shunt resistances, on the electrical properties of the sc. We assess the proposed device structure's performance using ideal values for the absorber layer thickness, buffer layer thickness, and doping concentration with silicon as the BSF(Back-Surface Field) layer. By optimizing the parameters in each layer, we achieve an efficiency of 20.83 %, which is higher than previous reports in the literature. These results provide a foundation for researchers to fabricate highly efficient CZTS solar cell in the future. In summary, our findings demonstrate the potential of CZTS solar cell with a BSF layer to significantly enhance the efficiency of solar devices, and pave the way for further exploration of this technology.

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.

A Deep Dive into Cu2ZnSnS4 (CZTS) Solar Cells: A Review of Exploring Roadblocks, Breakthroughs, and Shaping the Future.

Renewable energy is crucial for sustainable future, and Cu2ZnSnS4 (CZTS) based solar cells shine as a beacon of hope. CZTS, composed of abundant, low-cost, and non-toxic elements, shares similarities with Cu(In,Ga)Se2 (CIGS). However, despite its promise and appealing properties for solar cells, CZTS-based solar cells faces performance challenges owing to inherent issues with CZTS material, and conventional substrate structure complexities. This review critically examines these roadblocks, explores ongoing efforts and breakthroughs, providing insight into the evolving landscape of CZTS-based solar cells research. Furthermore, as an optimistic turn in the field, the review first highlights the crucial need to transition to a superstrate structure for CZTS-based single junction devices, and summarizes the substantial progress made in this direction. Subsequently, dive into the discussion about the fascinating realm of CZTS-based tandem devices, providing an overview of the existing literature as well as outlining the possible potential strategies for enhancing the efficiency of such devices. Finally, the review provides a useful outlook that outlines the priorities for future research and suggesting where efforts should concentrate to shape the future of CZTS-based solar cells.

Nitrogen doped single layer graphene for CZTS-based thin film solar cells

CdS thin films are commonly utilized as a buffer layer in chalcopyrite thin-film solar cells. However, due to the toxic nature of Cadmium (Cd), ongoing efforts are being directed towards exploring alternative options. In this contribution, doped graphene film with remarkable optical and electrical properties has been introduced for the first time as an alternative buffer layer, replacing CdS in CZTS thin-film solar cell application. In this study, nitrogen-doped graphene (N-doped graphene) film was utilized as a substitute buffer layer in the CZTS thin-film solar cell structure, replacing the conventional CdS thin film. For comparative analysis, CZTS/N-doped graphene and CZTS/CdS traditional solar cell structures were fabricated and separately characterized. The CZTS thin films produced were examined through EDX, XRD, SEM, Raman, optical transmission and PL spectroscopy measurements. According to performed analyses, the Cu-poor and Zn-rich kesterite CZTS thin films exhibited a uniform and dense polycrystalline microstructure as observed in surface and cross-sectional SEM images. XRD spectra of the kesterite CZTS thin film displayed predominant peaks corresponding to the (112), (220/204), and (312/116) diffraction planes of the kesterite CZTS phase. Raman spectra showed a dominant peak at ∼336 cm−1 associated with the kesterite CZTS phase. PL emission spectra indicated transitions from the conduction band to defect levels. The CVD-grown doped graphene film exhibited a 3.43 I2D/IG ratio and a 25 cm−1 FWHM of the 2D peak, indicating a single-layer graphene according to Raman analysis. Permanent nitrogen doping with a 2% atomic concentration was confirmed by XPS measurement. The optical transmission measurement of the single layer doped graphene film showed a 95% transmittance value. Nitrogen doping was contributed to decrease the sheet resistance of the graphene film. The Glass/Mo/CZTS/N-doped graphene/i-ZnO/ITO/Al solar cell displayed a VOC of 0.267 V, JSC of 24.6 mA/cm2, FF of 36.46, and η of 2.37%, showing higher FF and Jsc values but lower conversion efficiency compared to the Glass/Mo/CZTS/CdS/i-ZnO/ITO/Al traditional solar cell structure. Hence, the superior working function and transparency properties position the N-doped graphene film as a competitive buffer layer for use in CZTS-based thin-film solar cells.

The charm of entwining two major competitors CZTS & CH3NH3SnI3 to feasibly explore photovoltaic world beyond Shockley–Queisser limit

Many studies have reported CH3NH3SnI3-based solar cell having CZTS as hole transporter. In this paper, we have presented for the first time, an intensive analysis on CZTS-based solar cell device performance which has CH3NH3SnI3 as hole transporter. The proposed solar cell configuration is CH3NH3SnI3/CZTS/CdS/ZnO/AZO. The device optimization is performed in terms of layer thickness, carrier concentration, defect density, electron affinity, series resistance and shunt resistance. During optimization process, analysis of evolution in band structure, electric field, recombination rate and generation rate is utilized to provide proper explanation of device behavior. Finally, device is shown to perform very efficiently and reach highest efficiency value of 37.12 %. This sets up a new record in the history of theoretical development of CZTS-based solar cells. Moreover, it can be noted that the proposed experimentally-achievable solar cell has the potential to exceed the Shockley–Queisser limit for single-junction CZTS solar cells (32.1 %). The choice of CH3NH3SnI3 as an HTL in CZTS-based solar cell significantly enhances the electric field generation and substantially suppresses the recombination rate. Furthermore, the grace of series resistance optimization is discovered to lead to a very highly efficient device that performs beyond Shockley–Queisser limit.

Computational analysis on the role of an AGT current enhancer in a CZTS-based thin film solar cell

This paper gives a synopsis of a CZTS-based n-CdS/p-CZTS/p + -AgGaTe2/p++-MoS2 thin film solar cell that has been designed and explored by the simulation technique with the help of a solar cell capacitance simulator (SCAPS-1D). The design utilizes CdS as the window layer, CZTS as the first absorber layer, AgGaTe2 as the second absorber layer, and MoS2 as the BSF layer. The influencing parameters of these materials such as thickness, doping concentration, and defect density have been adjusted to achieve the right balance between the proposed structure and to see the changes that affect the device's overall performance. In ideal condition, the single n-CdS/p-CZTS heterojunction structure shows power conversion efficiency (PCE) of 17.75% with short circuit current, JSC of 24.82 mA/cm2, open circuit voltage, VOC of 0.88 V and fill factor (FF) of 81.3%. But, with the inclusion of MoS2 as the BSF, the overall PCE is elevated to 25.84% with VOC of 1.09 V, JSC of 26.96 mA/cm2 and FF of 87.64%. Finally, with the fusion of AgGaTe2 as a current augmenting layer the JSC gets a huge boost and is enhanced to 34.7 mA/cm2 with a PCE of 33.89%. These simulation findings unveil the potential of the proposed solar cell structure with CZTS as the absorber layer and AgGaTe2 as the current boosting layer in creating an environment-friendly, affordable and highly efficient thin film solar cell.

Numerical Study and Optimization of CZTS-Based Thin-Film Solar Cell Structure with Different Novel Buffer-Layer Materials Using SCAPS-1D Software

Numerical Study and Optimization of CZTS-Based Thin-Film Solar Cell Structure with Different Novel Buffer-Layer Materials Using SCAPS-1D Software

Photovoltaic properties of novel quaternary chalcogenides based on high-throughput screening and first-principles calculations

<sec>In recent decades, the demand for clean energy has promoted extensive research on solar cells as a key renewable energy source. Among the various emerging absorber layer materials, Kesterite-type semiconductors have aroused significant interest. Especially, Kesterite Cu<sub>2</sub>ZnSnS<sub>4 </sub>(CZTS) stands out as a promising candidate for low-cost thin-film solar cells due to its direct bandgap, high optical absorption coefficient, suitable bandgap (1.39–1.52 eV), and abundance of constituent elements. However, the power conversion efficiency (PCE) of CZTS-based solar cells currently lags behind that of Cu(In,Ga)Se<sub>2</sub> (CIGS) cells, mainly due to insufficient open-circuit voltage caused by a large number of disordered cations and defect clusters, resulting in non-radiative recombination and band-tail states.</sec><sec>To address these challenges, partial or complete cation substitution has become a viable strategy for altering the harmful defects in CZTS. This study proposes a heterovalent substitution of Zn in CZTS and explores the potential of novel quaternary chalcogenide compound <i>A</i><sub>2</sub><i>M</i><sub>2</sub><i>M'Q</i><sub>4</sub> (<i>A</i> = Na, K, Rb, Cs, In, Tl; <i>M</i> = Cu, Ag, Au; <i>M'</i> = Ti, Zr, Hf, Ge, Sn; <i>Q</i> = S, Se, Te) as absorbers for solar cells. By substituting elements in five prototype structures, a comprehensive material database comprising 1350 <i>A</i><sub>2</sub><i>M</i><sub>2</sub><i>M'Q</i><sub>4</sub> compounds is established.</sec><sec>High-throughput screening and first-principles calculations are used to evaluate the thermodynamic stabilities, band gaps, spectroscopic limited maximum efficiencies (SLMEs), and phonon dispersions of these compounds. Our research results indicate that 543 compounds exhibit thermodynamic stability (<i>E</i><sub>hull</sub> < 0.01 eV/atom), 202 compounds possess suitable band gaps (1.0–1.5 eV), and 10 compounds meet all the criteria for thermodynamic and dynamic stability, suitable band gaps, and high optical absorption performance (10<sup>4</sup>–10<sup>6</sup> cm<sup>–1</sup>), with theoretical SLME values exceeding 30%.</sec><sec>Notably, <i>Ibam</i>-Rb<sub>2</sub>Ag<sub>2</sub>GeTe<sub>4</sub> exhibits the highest SLME (31.8%) in these candidates, featuring a band gap of 1.27 eV and a small carrier effective mass (< <i>m</i><sub>0</sub>). The electronic structures and optical properties of these compounds are comparable to those of CZTS, which makes them suitable for highly efficient single-junction thin-film solar cells.</sec><sec>All the data presented in this work can be found at <ext-link ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.doi.org/10.57760/sciencedb.j00213.00006">https://www.doi.org/10.57760/sciencedb.j00213.00006</ext-link>.</sec>

Numerical modeling and performance analysis of a novel Cd-free all-Kesterite tandem solar cell using SCAPS-1D

Tandem solar cells have the potential to surpass conventional single-junction photovoltaics by harnessing a wider range of the solar spectrum and reducing losses caused by thermalization and transmission. This study examines the performance of a kesterite-kesterite tandem solar cell with two different absorber layers in each subcell using SCAPS-1D. The upper subcell comprises CZTS and ACZTS with wider bandgaps, while the lower subcell comprises ACZTSe and CZTSe with narrower bandgaps. The CZTS- and CZTSe-based solar cells were first validated using experimental data to determine the feasibility of the tandem solar cell design. The CZTS-based solar cell was modified by replacing the back contact, adding a Cd-free buffer layer of ZnMnO, and using a SnMnO2 layer as a window layer. The band gap and electron affinity of ZnMnO and SnMnO2 layers were adjusted by changing their manganese contents for optimal conduction band offset. A thin ACZTS layer was also added as a second absorber layer in the CZTS-based solar cell to enhance open circuit voltage. The CZTSe-based solar cell was thereafter modified by including an ACZTSe layer as a second absorber layer and by selecting ZnSe as a buffer layer and optimizing the thicknesses of all layers. Both upper and lower subcells were analyzed for tandem configuration using filtered spectra and current-matching techniques. The thickness of the CZTS layer in the upper subcell was adjusted to achieve current matching; consequently, the proposed tandem cell had an efficiency of ∼24%. These findings provide valuable insights for future advancements in kesterite-kesterite-based tandem solar cells.

Designing next-generation kesterite solar cells: A systematic numerical investigation of innovative structures and design variants for enhanced photovoltaic performance

This paper presents a thorough numerical investigation of copper zinc tin sulfide (CZTS)-based solar cells utilizing the SCAPS-1D simulation tool. In light of the scarcity of indium and gallium, CZTS is explored as a promising alternative absorber material. The study encompasses an extensive array of 280 device simulations, including a systematic optimization process targeting enhanced power conversion efficiency (PCE). Notably, this iterative optimization procedure results in a notable PCE increase from 11.01% to 14.24%. By delving into the realm of electron transport layer (ETL) materials, the integration of a CdO layer culminates in a significant PCE milestone of 15.71%, and a new structure was extrapolated from this step Back contact/CZTS/CdO/ZnO. Furthermore, an exploration involving 172 diverse configurations incorporating various hole transport layer (HTL) materials unveils a remarkable peak PCE of 21.14% (Back contact/SnS/CZTS/CdSe/ZnO). These findings provide valuable insights and directives for the advancement and optimization of CZTS-based solar cells.

Performance improvement of CZTS-based hybrid solar cell with double hole transport layer using extensive simulation

The extensive outcomes of the specific modeling method for hybrid photovoltaic solar cells at the illumination condition of AM 1.5G spectrum are shown in this simulation work. This research aims to optimize the efficiency of the device structures by introducing the novel hybrid-absorber layer (AL). The hybrid solar cell (HSC) has higher efficiency with an absorber layer (AL), i.e., Copper Zinc Tin Sulphide. The current simulation uses ZnO, V2O5, and Spiro-OMeTAD as the carrier transport layers (CTLs); both hole/electron transport layer (HTL/ETL) to sandwich the CZTS, which have precise bandgaps of 1.5 eV. Using double HTLs of Spiro-OMeTAD/V2O5 offers a high efficiency of 23.21%. The detailed examination of thickness, total defect density (DD), temperature dependency, and impedance-capacitance analysis of the simulated device structures are also studied simultaneously.

Improving the efficiency of ZnO/WS2/CZTS1 solar cells using CZTS2 as BSF layer by SCAPS-1D numerical simulation

With a high absorption coefficient and tunable bandgap CZTS (Copper Zinc Tin Sulfide) makes it suitable for photovoltaic applications. Present paper deals with the simulation and modeling of CZTS-based solar cells using tungsten disulfide (WS2) as the buffer layer and CZTS2 as the back surface field (BSF) layer to study the performance of the solar cell. Considering different physical and geometrical parameters such as thickness, acceptor density, interfacial defect density, and metal contact work functions the device calibration has been done. The temperature is varied from 300 K to 400 K to study the impact on device performance. The C-V and 1/C2 plot is presented to calculate the built-in voltage for the device. The series (Rs) and shunt (Rsh) resistance of 1 and 106 ohm.cm2 were kept throughout the simulation. The optimized thickness for the absorber, BSF, buffer, and window layers are 800 nm, 140 nm, 30 nm, and 90 nm respectively. The obtained results are validated using the experimental results available in the literature. Varying the values of different parameters, the optimal efficiency of 26% was reported in this work. Contrary to conventional solar cells, which contain expensive and toxic elements, WS2 may be a good option as a buffer layer in CZTS solar cells.

Manufacture of different oxides with high uniformity for copper zinc tin sulfide (CZTS) based solar cells

Herein, we investigate different oxides layers: Zinc Oxide (ZnO), Nickel Oxide (NiO), Titanium Oxide (TiO2), and Copper Oxide (CuO), which are effective materials for Copper Zinc Tin Sulfide (CZTS) based solar cells due to their excellent electrical and optical properties. The different oxide films were prepared using spray pyrolysis as a low-cost technique. Then, the films were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and UV–Visible to examine different properties. The XRD pattern showed that the different oxides are polycrystalline. ZnO exhibits a hexagonal wurtzite structure, and NiO is cubic. For the TiO2, (101) and (004) peaks have been identified, corresponding to the tetragonal anatase phase. CuO showed diffraction peaks corresponding to the monoclinic structures. The SEM results revealed that the deposited films consist of crystals with low crystallinity for NiO and good crystallinity for the rest oxides. The band gap was calculated from the UV–visible measurement. We obtained 3.26 eV, 3.34 eV, 3.2 eV, and 1.7 eV for ZnO, NiO, TiO2, and CuO respectively. The performance of the CZTS-based solar cell was checked by using the simulator SCAPS. ZnO and TiO2 were used as window layers where CZTS efficiencies are 24.40% and 24.54%, respectively. These findings show that ZnO and TiO2 films can be produced by low-cost techniques such as spray pyrolysis to be used as windows and electron transport layers for CZTS-based solar cells.

Analysis of various hole transport layers (HTLs) on the performance of CZTS- solar cell

CZTS is a potential absorber material and received a lot of focus because of its excellent optoelectronic properties. To improve the functionality of CZTS-based solar cells, this study examines the potential HTLs (MoTe2, Cu2O, and SnS) and their contribution to the better performance of the device. HTL improves the overall performance of the device by decreasing the recombination rate at the back contact and photon energy absorption. The impact of the various device parameters such as absorber layer thickness, defect densities, contact work functions, shunt and series resistances (RSh and Rs), and the temperature of the device are briefly examined in this work. The research shows that Cu2O and SnS are more emerged HTLs rather than MoTe2. The device achieved a PCE of 24% and a FF of 74%. The results show that the addition of these HTLs significantly improved the Voc, Jsc, and FF, all of which are within the Shockley-Queasier limits. This study points to the possibility of producing more efficient CZTS heterojunction-based solar cells.

Cu2ZnSnS4 monograin layer solar cells for flexible photovoltaic applications.

Monograin powder technology is one possible path to developing sustainable, lightweight, flexible, and semi-transparent solar cells, which might be ideal for integration with various building and product elements. In recent years, the main research focus of monograin technology has centered around understanding the synthesis and optoelectronic properties of kesterite-type absorber materials. Among these, Cu2ZnSnS4 (CZTS) stands out as a promising solar cell absorber due to its favorable optical and electrical characteristics. CZTS is particularly appealing as its constituent elements are abundant and non-toxic, and it currently holds the record for highest power conversion efficiency (PCE) among emerging inorganic thin-film PV candidates. Despite its advantages, kesterite solar cells' PCE still falls significantly behind the theoretical maximum efficiency due to the large VOC deficit. This review explores various strategies aimed at improving VOC losses to enhance the overall performance of CZTS monograin layer solar cells. It was found that low-temperature post-annealing of CZTS powders reduced Cu-Zn disordering, increasing Eg by ∼100 meV and VOC values; however, achieving the optimal balance between ordered and disordered regions in kesterite materials is crucial for enhancing photovoltaic device performance due to the coexistence of ordered and disordered phases. CZTS alloying with Ag and Cd suppressed non-radiative recombination and increased short-circuit current density. Optimizing Ag content at 1% reduced CuZn antisite defects, but higher Ag levels compensated for acceptor defects, leading to reduced carrier density and decreased solar cell performance. Co-doping with Li and K resulted in an increased bandgap (1.57 eV) and improved VOC, but further optimization is required due to a relatively large difference between measured and theoretical VOC. Heterojunction modifications led to the most effective PCE improvement in CZTS-based solar cells, achieving an overall efficiency of 12.06%.

Influence of dopants in the buffer layer on CZTS solar cell performance

Copper zinc tin sulfide (CZTS) has commanded the next generation of solar cell materials because of its superior performance, lower cost and abundant availability on earth. This study examined the impact of different dopants in the buffer layer on the electrical characteristics of solar cells. For the n-indium tin oxide/cadmium sulfide (CdS) (silver (Ag)–cadmium sulfide, copper (Cu)–cadmium sulfide and chlorine (Cl)–cadmium sulfide)/CZTS/molybdenum (Mo) proposed device structure of a solar cell, the doping concentration and thickness of the buffer and absorber layers were examined. The silver–cadmium sulfide buffer layer was shown to be one of the best options for manufacturing a buffer layer for a CZTS-based solar cell in this study. The doping concentration and thickness of the solar cell were optimized in this work. This work obtained a higher than 21% efficiency when using silver–cadmium sulfide as a dopant in the cadmium sulfide buffer layer. Numerical modeling of the proposed structure revealed a unique method for improving the efficiency of a CZTS solar cell. The findings of this study are expected to be utilized in the interest of the many researchers working in this field.