Reverse Saturation Current Density Research Articles

Optimizing Charge Transport and Band-Offset in Silicon Heterojunction Solar Cells: Impact of TiO2 Contact Deposition Temperature

Abstract Carrier selective contacts are a primary requirement for fabricating silicon heterojunction solar cells (SHSCs). TiO2 is a prominent carrier selective contact in SHSCs owing to its excellent optoelectronic features such as suitable band offset, work function, and cost-effectiveness. Herein, we fabricated simple SHSCs in an Al/TiO2/p-Si/Ti/Au device configuration. Ultrathin 3 nm TiO2 layers were deposited onto a p-type silicon substrate using the atomic layer deposition method. The deposition temperature of TiO2 layers varied from 100 °C to 250 °C. X-ray photoelectron spectroscopic studies suggest that deposition temperature highly affects the chemical states of TiO2 and reduces the formation of defective state densities at the Fermi energy. The optical band gap values of TiO2 layers are also altered from 3.13 eV to 3.27 eV when the deposition temperature increases. The work function tuning from -5.13 eV to -4.83 eV has also been observed in TiO2 layers, suggesting the variation in Fermi level tuning, which arises due to changes in carrier concentrations at higher temperatures. Several device parameters, such as ideality factor, trap density, reverse saturation current density, barrier height, etc., have been quantified to comprehend the effects of deposition temperature on photovoltaic device performance. The results suggest that the deposition temperature significantly influences the charge transport and device performance. At an optimum temperature, a significant reduction in charge carrier recombination and trap state density has been observed, which helps to improve power conversion efficiency.

A high effciency (11.06 %) CZTSSe solar cell achieved by combining Ag doping in absorber and BxCd1-xs/caztsse heterojunction annealing

Many literatures have demonstrated that a smaller amount of Ag doping in Cu2ZnSn(S, Se)4 (CZTSSe) can elevate the open-circuit voltage (Voc) and fill factor (FF) of CZTSSe solar cells, but decrease short-circuit current density (Jsc) due to the increase in bandgap (Eg) of the CAZTSSe by Ag doping. The decreased Jsc limits the enhancement in PCE through Ag doping. In this paper, to compensate for the deficit in Jsc and further increase Voc and FF, a strategy is proposed to substitute CdS/CAZTSSe in CAZTSSe solar cells with annealed B-doped CdS/CAZTSSe. It is found that B doping can increase the electron density of CdS (ne) and decrease the lattice mismatch between CdS and CAZTSSe. Annealing can decrease the hole density of CAZTSSe (np) and passivate the surface of CAZTSSe by diffusing B towards the surface of CAZTSSe. The increased ne and reduced np widen the depletion region, leading to an increase in photogenerated carrier density (JL), resulting in an increase in Jsc. The surface passivation and decreased lattice mismatch can reduce interfacial recombination, resulting in decrease in the reverse saturation current density (J0), so further increases in Voc and FF. By optimizing the Ag doping content, B doping content, as well as the annealing temperature and time of the BxCd1-xS/CAZTSSe, the power conversion efficiency (PCE) increases from 8.96 % to 11.06 %. This study not only advances a deeper understanding of the mechanisms behind various parameters in CZTSSe solar cells but also proposes a method to boost the PCE of CZTSSe solar cells.

Non-covalent functionalized Schottky interface at Ti3C2Tx/c-Si van der Waals heterojunction

Synergistic interaction between 2D materials and organic molecules presents an additional dimension for tuning their intrinsic properties. Herein, we aim totune the work function of 2D Ti3C2Txby introducing ultrathin interlayers of organic dipoles (O.D.) with a defined dipole moment value. Interface engineering is achieved through the inclusion of poly(ethylene)amine (PEI 0.1 %) and third generation poly(amido-)amine (PAMAM G3), between the Ti3C2TXand c-Si. c-Si/O.D./Ti3C2Tx heterostructures were fabricated by simple drop casting of the aqueous MXene solution on O.D. coated c-Si substrates. Charge transport properties of the fabricated Schottky diodes with structure of c-Si/O.D./Ti3C2TXwere evaluated through systematic analysis of the I-V and C-V characteristics. Our investigations reveal that diodes featuring O.D. as interlayers exhibit substantially reduced reverse saturation current density (J0) and enhanced built-in potential (Vbi).Work function of the fabricated c-Si/MXene/O.D. structures were evaluated from the ultraviolet photo-emission spectroscopy (UPS) measurements. We report a significant reduction in the work function value of Ti3C2Txfrom 5.8 eV to 4.2 eV for Ti3C2Tx/PEI 0.1 % and 3.3 eV for Ti3C2Tx/PAMAM-G3 heterostructures. Our studyintroduces an innovative approach for modifying the work function of Ti3C2Tx through the incorporation of O.D., highlighting the versatility of MXene electrodes to shape the future optoelectronic devices.

Enhancing the efficiency of air-processed (Cu, Ag)2ZnSn(S, Se)4 solar cells by regulating the band tail and interface recombination

Air-processed kesterite solar cells show excellent prospects for commercial application because they are suitable for large-scale production. This study shows how the power conversion efficiency (PCE) of (Cu, Ag)2ZnSn(S, Se)4 solar cells can be improved by adjusting the annealing time during the selenization process at a low temperature of 70 °C. Enhancement of PCE is achieved when the annealing time is 240 s. The primary determinant of enhanced PCE is a reduction in reverse saturation current density (J0) and ideality factor (A). Examination of depth characterization indicated that the decrease in J0 and A can be ascribed to the inhibition of [2CuZn + SnZn] defects cluster, which is mainly accountable for the band tail states, and the suppression of interface recombination.

Improvement of Efficiency in Kesterite Solar Cells by Intentionally Inserting a Thin MoS2 Layer into the Back Interface.

A Mo(S,Se)2 interfacial layer is formed inevitably and uncontrollably between the Mo electrode and Cu2ZnSn(S,Se)4 (CZTSSe) absorber during the selenization process, which significantly influences the performance of CZTSSe solar cells. In this work, an ultrathin MoS2 layer is intentionally inserted into Mo/CZTSSe to reduce the recombination and thus optimize the interface quality. It is revealed that the absorber exhibits a continuous and compact morphology with bigger grains and remarkably without pinholes across the surface or cross-sectional regions after MoS2 modification. Benefitting from this, the shunt resistance (RSh) of the device increased evidently from ∼395 to ∼634 Ω·cm2, and simultaneously, the reverse saturation current density (J0) realized an effective depression. As a result, the power conversion efficiency (PCE) of the MoS2-modified device reaches 9.64% via the optimization of the thickness of the MoS2 layer, indicating performance improvements with respect to the MoS2-free case. Furthermore, the main contribution to the performance improvement is derived and analyzed in detail from the increased RSh, decreased J0, and diode ideality factor. Our results suggest that the Mo/CZTSSe interface quality and performance of CZTSSe solar cells can be modulated and improved by appropriately designing and optimizing the thickness of the inserted MoS2 layer.

Unveiling the mechanism of attaining high fill factor in silicon solar cells

AbstractA world record conversion efficiency of 26.81% has been achieved recently by LONGi team on a solar cell with industry‐grade silicon wafer (274 cm2, M6 size). An unparalleled high fill factor (FF) of up to 86.59% has also been certified in a separated device. The theoretical FF limit has been predicted to be 89.26%, while the practical FF is far below this limit for a prolonged interval due to the constraints of recombination (i.e., SRH recombination) and series resistance. The ideality factor (m) in the equivalent circuit of silicon solar cells is consistently ranging from 1 to 2 and rarely falls below 1, resulting in a relatively lower FF than 85%. Here, this work complements a systematic simulation study to demonstrate how to approach the FF limit in design of silicon solar cells. Firstly, a diode component with an ideality factor equal to 2/3 corresponding to Auger recombination is incorporated in the equivalent circuit for LONGi ultra‐high FF solar cell; Secondly, an advanced equivalent circuit is put forward for comprehensive analysis of bulk recombination and surface recombination on the performance, in which specific ideality factors are directly correlated with various recombination mechanisms exhibiting explicit reverse saturation current density (J0). Finally, we evaluate precisely the route for approaching theoretical FF in practical solar cell fabrication based on electrical design parameters using the developed model.

Indium content, doping and thickness related impacts on nonpolar (In,Ga)N solar cell performance: Numerical investigation

Analytical model to evaluate the photovoltaic performance via the short circuit current density, open circuit voltage, fill factor, and efficiency of nonpolar (In,Ga)N solar cells at room temperature is conducted via this paper. The Indium content and structure thickness including the doping concentration impacts are assessed to obtain the optimum values that yield high efficiencies. The band gap energy, reverse saturation current density, and carrier mobility are the important factors that govern how the solar cell performance characteristics change with the adjusted parameters. The solar cell characteristics are calculated for American Society for testing and Materials experimental data related to 1-sun AM1.5D, AM1.5G, and AM0 spectra. A high quality In0.42Ga0.58N(1.42eV) solar cell with a 3μm thickness, 1017cm−3 doping concentration and reflection coefficient of about 15% can display as optimum efficiency as 25.43%,25.16% and 22.87% under respectively 1-sun AM1.5G, AM1.5D and AM0 illuminations. The optimum AM1.5G related photovoltaic conversion efficiency is reached for FF=89.2%, Voc=1.12V and Jsc=28.63mA.cm−2.

Influence of Al doping in zinc oxide electron transport layer for the degradation triple-cation-based organometal halide perovskite solar cells

Various strategies have been adapted to fabricate stable organic-inorganic hybrid perovskite (PVT) solar cells (PSCs). The triple-cation (CH3NH3+ (MA+), CH3(NH2)2+ (FA+), and Cs+) along with dual-anion (I− and Br−)-based PVT (TC-PVT) layer offers better stability than single cation-based PVTs. The deprivation of the PVT absorber is also influenced by the interface of the absorber with the charge transport layer (electron transport layer (ETL) and hole transport layer (HTL)). Here, the degradation of the TC-PVT coated on Al-doped zinc oxide (AZO) as well as FTO/AZO/TC-PVT/HTL structured PSC was examined for various Al to Zn molar ratio (RAl/Zn) of AZO. The PL decay study of FTO/AZO/TC-PVT revealed that the lowest degradation in the power (35.38%) was observed for the AZO with RAl/Zn of 5%. Furthermore, the PV cell parameters of the PSCs were analytically determined to explore the losses in the PSCs during degradation. The shunt resistance reduction was maximum (50.32%) for RAl/Zn = 10%, whereas, minimum shunt loss (7.33%) for RAl/Zn of 2%. The highest loss due to series resistance was observed for RAl/Zn of 0%. The changes in diode ideality factor (n) and reverse saturation current density (J0) were the smallest for RAl/Znof 10%.

Influence of synthesis parameters of N-doped graphene quantum dots and polymer composite layer on the performance of CIGS solar cells

In this work, N-doped graphene quantum dots (N-GQDs) are used as luminescent downshifting layers, which enhanced the performance of the CIGS solar cells. For providing mechanical strength and chemical stability, a poly(methyl methacrylate) (PMMA) polymer-based matrix is used. However, the PMMA layer creates photoluminescence (PL) quenching, so N-GQDs/PMMA layer is annealed at various temperatures (20–80 °C) to obtain the best performance. These layers were applied on the top of the CIGS solar cells and the performance of the cell is evaluated. The best value of η is obtained for 60 °C. The Jsc and η values are enhanced to 36.03 mA/cm2 and 16.13% from 34.05 mA/cm2 and 14.70%, respectively. Furthermore, the PV cell parameters (photogenerated current density (Jph), shunt resistance (Rsh), series resistance (Rs), diode ideality factor (n), and reverse saturation current density (J0)) were also determined and analyzed to investigate the reduction in losses in the cell.

Commercial carbon nanotube as rear contacts for industrial p-type silicon solar cells with an efficiency exceeding 23%

Commercially available single wall carbon nanotube (SWCNT) soots are combined with an organic passivation scheme and shown to be an efficient rear contact and alternative to ALD-Al2O3/PECVD-SiNx/laser treatment in conventional passivated emitter and rear cell (PERC) solar cells. Both low carbonaceous purity 60–70% and 95% SWCNTs are tested and a power conversion efficiency of over 23% is demonstrated. The approach is simple, scalable and completely eliminates the metal-semiconductor contact known to cause high interfacial recombination in PERC technology. A low reverse saturation current density (J0) is achieved by varying the concentration and species of SWCNTs used and a full-area back surface field on an industrial sized (275.54 cm2) solar cell is obtained.

Efficiency enhancement of Cu2ZnSn(S, Se)4 solar cells by addition a CuSe intermediate layer between Cu2ZnSn(S, Se)4 and Mo electrode

A CuSe intermediate layer (IL) is prepared between CZTSSe and Mo electrode to decay the carrier recombination on the rear surface of the CZTSSe absorber. The power conversion efficiency (PCE) can be increased from 7.52% to 10.09% by optimizing the thickness of CuSe IL. The increased PCE comes from improvement in filling factor (FF), short-circuit current density (JSC), and open-circuit voltage (VOC), and their contribution percent is calculated to be 63.08%, 24.83%, and 12.09%, respectively. It is demonstrated that boosted FF is mainly due to decreased reverse saturation current density (J0), raised JSC owing to higher photogenerated current density (JL), and enhanced VOC caused by decreased J0 and higher JL. The contribution percent of (ideal factor (A), J0), JL, Rs, and shunt resistance (Rsh) to increased PCE is calculated to be 60.84%, 27.41%, 10.33%, and 1.42%, respectively. By experimental characterization and SCAPS-1D simulation, it is suggested that decreased J0 results from the formation of passivation field and high electron potential barrier at the rear surface of CZTSSe due to the addition of suitable thickness CuSe IL, higher JL from the increase in width of the depletion region of CZTSSe/CdS, lower Rs from decrease in thickness of Mo(S, Se)2, and bigger Rsh from improved crystal quality of CZTSSe absorber.

Defect-control electron transport behavior of gallium nitride/silicon nonplanar-structure heterojunction

Compared with a traditional heterojunction, a nonplanar-structure heterojunction can reduce the problems caused by a lattice mismatch through a three-dimensional stress release mechanism, which will be helpful for promoting the performance and stability of related devices. In this paper, we report our study on the electron transport behavior of a gallium nitride (GaN)/silicon (Si) heterojunction with nonplanar-structure interface, which was prepared through growing GaN on a hierarchical structure, Si nanoporous pillar array (Si-NPA). To clarify the electron transport mechanism and promote the device performance, annealing treatment in ammonia atmosphere was carried out to as-prepared GaN/Si-NPA. The formation of the heterojunction was verified by the typical rectification behavior observed in both as-prepared and annealed samples. After annealing treatment, a lower turn-on voltage, a smaller reverse saturation current density, a larger forward current density and a higher reverse breakdown voltage were obtained, which indicate the promotion of the heterojunction performance. By comparatively studying the spectrum evolution of photoluminescence before and after annealing treatment, the underlying mechanism is clarified as the variation of the type and density of point defects such as gallium vacancy (V Ga), oxygen substitutional impurity (ON), and their complex defect V Ga−ON in GaN. The results illustrate an effective defect-control strategy for optimizing the performance of GaN/Si heterojunction optoelectronic devices.

Improvement of power conversion efficiency of Cu2ZnSn(S,Se)4 solar cells by Al doped CdS

In this work, we substituted Al doped CdS(CdS:Al) for CdS buffer layer of Cu2ZnSn(S,Se)4 (CZTSSe) solar cell to increase built-in field and decrease interface recombination, and studied influence of this substitution on power conversion efficiency (PCE) of CZTSSe solar cell. It is found that the PCE can be increased from 6.57% to 8.99% by substituting CdS:Al with Al doping concentration of 3.3 at% for CdS. The increased PCE is mainly attributed to increase in photogenerated current density (JL) and decrease in reverse saturation current density (J0). Mechanisms of increase in JL and decrease in J0 are suggested by analysis of influence of change of bandgap, transmission, electron density and lattice constants of CdS induced by Al doping on light intensity passing through CdS, built-in field and lattice mismatch of CZTSSe/CdS heterojunction. This strategy provides a rational design for optimizing the heterojunction of CZTSSe solar cells to achieve high efficiency.

Improvement of Photovoltaic Performance of Cu2ZnSn(S,Se)4 Solar Cells by Modification of Back Electrode Interface with Amorphous Boron Nitride

AbstractAn amorphous boron nitride (aBN) layer is inserted between Cu2ZnSn(S,Se)4 (CZTSSe) films and Mo back electrode of CZTSSe solar cell by magnetron sputtering to mitigate the carrier recombination at back interface by tuning energy band alignment and suppressing formation of secondary phases and Mo(S,Se)2. The effect of the aBN layer on power conversion efficiency (PCE) of CZTSSe solar cell is investigated by numerical simulation and experiment. It is found that PCE is greatly improved via the insertion of suitable thick aBN layer, which is attributed to increased open‐circuit voltage (VOC) and fill factor (FF). By quantitative analysis, it is deduced that the increased VOC originates mainly from decrease in reverse saturation current density (J0), followed by increase in shunt resistance (RSh), and the increased FF is mainly due to the decreased J0, followed by increased RSh and decreased photogenerated current density (JL). By optimizing aBN thickness through tuning sputtering time, the PCE increases from 8.68% of CZTSSe solar cell without the aBN layer to 9.51% of the CZTSSe solar cell with aBN layer. The influence mechanism of the aBN layer on the PCE is suggested by analyzing quantitatively the effect of the aBN layer on JL and electrical parameters.

A study on passivation improvement in n-passivated emitter rear totally diffused solar cell using rapid thermal annealing

An investigation on enhanced surface passivation in the existing industrial process line of large area n-type silicon (Si) Passivated Emitter Rear Totally diffused ( n- PERT) solar cell has been performed. The Rapid Thermal Process (RTP) optimization for 20 min is conducted in the temperature range of 500–900°C and device evaluation is carried out with respect to regularly processed n-PERT solar cell. The impact of pre-metallization annealing is studied with the support of cell parameters like shunt resistance, reverse saturation current density determined from current-voltage measurements. The enhanced surface passivation via hydrogenation from silicon nitride (SiNx) layer during annealing is established with the help of external quantum efficiency, spectral response measurements and Fourier transform infrared spectroscopy analysis. The addition of optimized annealing resulted in improvement by 550% (from 38 to 247 µs), 7.73% (from 630.7 to 678.8 mV) and 84.77% (from 223.3 to 34 cm/s) in effective minority carrier lifetime, implied open circuit voltage and surface recombination velocity respectively. Finally, RTP technique for optimized process line has been successfully incorporated in industrial high-volume batch of 140898 CZ n-type Si wafers, which predicts conceptual validation of the study in mass scale production line with an increment in average efficiency of the device by 0.35%.

Comparison of electrical characteristics of Schottky junctions based on CdS nanowires and thin film

CdS nanowires and film Schottky diodes are fabricated and diode properties are compared. Effect of SnO2 on CdS film diode properties is investigated. CdS film/Au on 100 nm SnO2 substrate demonstrates like-resistor characteristics and increase in SnO2 thickness corrects resistor behavior, however the effective reverse saturation current density J o is significantly high and shunt resistance are considerably low, implying that SnO2 slightly prevents impurities migration from CdS films into ITO but cause additional issues. Thickness of CdS film on diode properties is further investigated and increasing CdS film thickness improved J o by one order of magnitude, however shunt resistance is obviously low, suggesting intrinsic issues in CdS film. 100 nm CdS nanowire/Au diodes reduce J o by three orders of magnitude in the dark and two orders of magnitude in the light respectively and their shunt resistance is significantly enhanced by 70 times when comparing with those of the CdS film diodes. The wide difference can be attributed to the fact that CdS nanowires overcome intrinsic issues in CdS film and thus demonstrate significantly well- defined diode behavior. Simulation found that CdS nanowire diodes have low compensating acceptor type traps and interface state density of 5.0 × 109 cm−2, indicating that interface recombination is not a dominated current transport mechanism in the nanowire diodes. CdS film diodes are simulated with acceptor traps and interface state density increased by two order of magnitude and shunt resistance reduced by one order of magnitude, indicating that high density of interface states and shunt paths occur in the CdS film diodes.

Role of zinc tin oxide passivation layer at back electrode interface in improving efficiency of Cu2ZnSn(S,Se)4 solar cells

We report a Cu2ZnSn(S,Se)4 (CZTSSe) solar cell with a modified structure via inserting an intermediate zinc tin oxide (ZTO) layer between Mo electrode and CZTSSe layer in the conventional CZTSSe solar cell. Comparing with the conventional CZTSSe solar cells (without ZTO layer), the best photovoltaic performance is obtained for the solar cells with a modified structure. When an 8-nm-thick ZTO passivation layer is inserted, the corresponding device shows the improvements in performance parameters, including short-circuit current density (JSC), open-circuit voltage (VOC), and fill factor (FF). As a result, we obtained a maximum power conversion efficiency (PCE) of 8.95% for the optimized device with an 8-nm-thick ZTO layer, which is ascribed to the increase of shunt resistance (RSh), decrease of series resistance (RS) and decrease of reverse saturation current density (J0). Our results suggest that the ZTO is a promising passivation material at back electrode interface for optimizing the performance and improving efficiency of CZTSSe-based solar cells.

Comparative study on effect of Mo–Cr bilayer and Mo back electrodes on performance of Cu2ZnSn(S, Se)4 solar cell

In the present work, Mo–Cr bilayer back electrode is prepared and used in Cu2ZnSn(S, Se)4 (CZTSSe) solar cells, to enhance adhesion of Mo to soda lime glass (SLG) substrate and so improve power conversion efficiency (PCE) of CZTSSe solar cell. It is found that the Mo–Cr bilayer electrode has smaller resistivity and stronger adhesion to SLG than conventional Mo electrode. CZTSSe film grown on the Mo–Cr electrode has better crystal quality and closer contact with back electrode than that grown on Mo electrode. Compared to Mo electrode, Mo–Cr bilayer electrode can improve open-circuit voltage; short-circuit current density and filling factor and so PCE of CZTSSe solar cell. By optimizing process, the PCE of CZTSSe solar cell is increased from 8.4% (7.9% for total area) with Mo as electrode to 9.6% (9.0% for total area) with Mo–Cr as electrode. The increment of the PCE is mainly attributed to increase in open circuit voltage (Voc) and filling factor (FF). The increased FF and Voc are due to decrease in series resistance and reverse saturation current density induced by substitution of Mo–Cr for Mo, respectively.

Monolithic two-color short-wavelength InGaAs infrared photodetectors using InAsP metamorphic buffers

A bias-selectable two-color heterojunction bandgap engineered InGaAs thin film infrared photodetector, monolithically grown on an InP substrate by metal–organic chemical vapor deposition, is demonstrated. The detector structure has two back-to-back diodes, with In0.53Ga0.47As and In0.83Ga0.17As absorbers separated by n+-InAsxP1-x metamorphic buffers to accommodate for the lattice mismatch between the absorbers of ∼2%. The surface of the topmost metamorphic buffer of InAs0.63P0.37, acting as a lattice-matched virtual substrate for the In0.83Ga0.17As absorber, has a Gaussian height distribution with a low surface roughness of 2.8 nm. The InAsxP1-x buffers achieve a gradual lattice constant transition from In0.53Ga0.47As to In0.83Ga0.17As, with a sufficient strain relaxation of 97%. Compared to the In0.53Ga0.47As diode, the In0.83Ga0.17As diode shows a higher reverse saturation current density by a factor of approximately 104, owing to a shorter minority carrier lifetime and a higher intrinsic carrier concentration. The bias-dependent two-color detection at the cutoff wavelengths of 1.7 μm and 2.6 μm is achieved, enabled by the In0.53Ga0.47As (blue channel) and In0.83Ga0.17As (red channel) absorption, respectively. The two-color InGaAs photodetector exhibits high specific detectivities of 4.1×1011 and 3.1×109 cm·Hz1/2/W at 300 K in both the blue and red channel regions, respectively.

Fabrication of closed-space sublimation Sb2(S1-xSex)3 thin-film based on a single mixed powder source for photovoltaic application

Because of favourable stability, facile fabrication, non-toxicity, tunable bandgap and high extinction coefficient, Sb 2 (S 1-x Se x ) 3 combined the advantages of Sb 2 S 3 and Sb 2 Se 3 have attracted extensive attention. Unlike previous studies using a preformed target or source of a single composition, our study offered a high‐throughput closed-space sublimation method based on a single mixed powder source of Sb 2 S 3 and Sb 2 Se 3 . We fabricated single-phase and highly crystalline Sb 2 (S 1-x Se x ) 3 films with strong (221) orientation, which is beneficial for the rapid transmission of photon-generated carriers. The bandgap of films evolved from 1.79 eV to 1.38 eV that accompany the varying x value of Se content from 0.14 to 0.85. The corresponding solar cells with the structure of FTO/CdS/Sb 2 (S 1-x Se x ) 3 /Au were fabricated, and then the relationship between performance, source temperature and alloy composition were investigated. The open-circuit voltage and short circuit current density showed opposite trends with increased Se content. Finally, the champion device with a PCE of 2.70% was obtained employing Sb 2 (S 0.25 Se 0.75 ) 3 absorber, which had optimal grain orientation, favourable surface morphology. The bandgap is 1.45 eV, which falls into the ideal bandgap in the Shockley–Queisser limit. A low reverse saturation current density (2.35 × 10 −5 mA/cm 2 ) and the relevant diode ideality factor (1.38) were obtained, which implies favourable junction quality. The CSS technique is expected to improve production efficiency and promote Sb 2 (S 1-x Se x ) 3 solar cell commercial applications, worth further optimization.