Sb2S3 Absorber Research Articles

Additive engineering for Sb2S3 indoor photovoltaics with efficiency exceeding 17%

Indoor photovoltaics (IPVs) have attracted increasing attention for sustainably powering Internet of Things (IoT) electronics. Sb2S3 is a promising IPV candidate material with a bandgap of ~1.75 eV, which is near the optimal value for indoor energy harvesting. However, the performance of Sb2S3 solar cells is limited by nonradiative recombination, which is dependent on the quality of the absorber films. Additive engineering is an effective strategy to fine tune the properties of solution-processed films. This work shows that the addition of monoethanolamine (MEA) into the precursor solution allows the nucleation and growth of Sb2S3 films to be controlled, enabling the deposition of high-quality Sb2S3 absorbers with reduced grain boundary density, optimized band positions, and increased carrier concentration. Complemented with computations, it is revealed that the incorporation of MEA leads to a more efficient and energetically favorable deposition for enhanced heterogeneous nucleation on the substrate, which increases the grain size and accelerates the deposition rate of Sb2S3 films. Due to suppressed carrier recombination and improved charge-carrier transport in Sb2S3 absorber films, the MEA-modulated Sb2S3 solar cell yields a power conversion efficiency (PCE) of 7.22% under AM1.5 G illumination, and an IPV PCE of 17.55% under 1000 lux white light emitting diode (WLED) illumination, which is the highest yet reported for Sb2S3 IPVs. Furthermore, we construct high performance large-area Sb2S3 IPV minimodules to power IoT wireless sensors, and realize the long-term continuous recording of environmental parameters under WLED illumination in an office. This work highlights the great prospect of Sb2S3 photovoltaics for indoor energy harvesting.

Grain engineering of solution-processed Sb2S3 thin film by tuning precursor fabrication environments

Antimony sulfide (Sb2S3) has garnered significant attention recently due to its remarkable photovoltaic properties and low toxicity. However, the conventional physical vapor deposition approach faces challenges in achieving high-quality films due to Sb2S3 having a quasi-one-dimensional nanoribbon structure. In contrast, solution-processed Sb2S3 thin films have shown improved photovoltaic behavior, offering a low-cost and scalable fabrication method. Nonetheless, the sensitivity of the solution process to the chemical composition of the precursor poses a challenge, often requiring noble gas protection to prevent exposure to toxic solvents or moisture-sensitive chemicals. Despite this, the impact of precursor fabrication conditions on film growth behavior remains unexplored. In our study, we investigate how different processing atmospheres of precursors, namely nitrogen (N2) and air, affect grain growth and the associated optical and electronic performance of Sb2S3 thin films. Our findings reveal that the presence of oxygen in the precursor can hinder grain growth by obstructing surface integration sites, resulting in undesired (hk0) orientation and even the formation of Sb2O3 on the surface of the Sb2S3 films, despite identical post-deposition conditions. This research sheds light on how the ambient conditions during precursor preparation can influence grain engineering, thereby providing valuable insights for controlling the grain size and producing high-quality Sb2S3 absorber films.

Hydrothermally deposited Sb2S3 absorber, and a Sb2S3/CdS solar cell with VOC approaching 800 mV

We report the hydrothermal deposition of Sb2S3 thin film on top of CdS buffer layer, and the fabrication of prototype photovoltaic devices utilizing spiro-OMeTAD as the hole transport layer. The as-deposited films were amorphous, which transformed to polycrystalline after thermal processing. The pristine films were annealed at different temperatures and showed effective recrystallization at 350 °C which resulted in larger grains, intense XRD patterns, and significantly improved device parameters. The obtained VOC of 795 mV is among the highest reported for a Sb2S3 based solar cell. Deep level transient spectroscopy studies detected an electron trap with activation energy 0.61 eV in the pristine annealed absorber, which became deeper (0.66 eV) upon Na incorporation. However, the capture cross-section decreased by an order of magnitude, and the trap density halved. The reduction in the capture cross-section and trap density for the Na-incorporated device coincides with the improved EQE response in the mid- and long-wavelength regions and a 9 % increase in device efficiency. The light intensity dependence of VOC clearly demonstrated that Na incorporation reduced the trap-assisted recombination and facilitated efficient charge transport in the device.

Efficient CdS/Sb2S3 interfacial modification using sodium borohydride etching for enhanced performance of low-cost full-inorganic antimony-based solar cells

Antimony sulfide (Sb2S3) is a promising material for photovoltaic applications because of its high absorption coefficient, environmental friendliness and low cost. Nevertheless, the conversion efficiency of Sb2S3 solar cells severely deviates from theoretical predictions, and the interface between CdS and Sb2S3 is crucial for the overall performance. In this study, we conducted a highly effective sodium borohydride (NaBH4) etching to modify the CdS/Sb2S3 interface, aiming to improve the device performance. The NaBH4 etching led to a reduction in surface roughness and an enhancement in the hydrophilicity of the CdS layer, creating a more conducive environment for the subsequent deposition of the Sb2S3 absorber layer. Simultaneously, the reduction of cadmium oxide serves to optimize interfacial energy alignment and minimize recombination losses. Ultimately, our full-inorganic Sb2S3 solar cells, featuring the configuration FTO/CdS/Sb2S3/MnS/Carbon, attain a PCE of 6.26%. This marks a significant improvement of 15% compared to cells without NaBH4 etching. This study presents a feasible and efficient perspective for modifying the CdS/Sb2S3 interface, thereby enhancing the performance of Sb-based solar cells.

Investigation of the Performance of a Sb2S3-Based Solar Cell with a Hybrid Electron Transport Layer (h-ETL): A Simulation Approach Using SCAPS-1D Software

In order to reduce current leakage and improve electron transfer in solar cells, charge transport layers (CTL), mainly hybrid electron transport layers (h-ETL), are considered as a solution. In this research contribution, computational analysis using SCAPS-1D software is performed to explore the output photovoltaic parameters of a Sb2S3-based solar cell with h-ETL. No theoretical works on this configuration have been previously reported. The main objectives of the present work are to propose a h-ETL with good band alignment with the Sb2S3 absorber, high transparency, and Cd free; to mitigate the instability and cost issues associated with using Spiro-OMeTAD HTL; and to optimize the solar cell. Thus, we calibrated the J-V characteristics and electrical parameters of the FTO/(ZnO/TiO2)/Sb2S3/Spiro-OMeTAD/Au solar cell by numerical simulation and compared them with those of the experiment. Subsequently, our simulations show that to replace the TiO2 ETL used in the experiment and to form the h-ETL with ZnO, IGZO is found to be a good candidate. It has better band alignment with the Sb2S3 absorber than TiO2 ETL, which reduces the trap states at the ETL/Sb2S3 interface; it has high transparency due to its wide bandgap; and an intense electric field is generated at the IGZO/Sb2S3 interface, which reduces the recombination phenomenon at this interface. MoO3, MASnBr3, Cu2O, CuI, and CuSCN HTL were also tested to replace the Spiro-OMeTAD HTL. Simulation results show that the cell with MoO3 HTL achieves higher performance due to its high hole mobility and high quantum efficiency in the visible region; it also allows the solar cell to have better thermal stability (TC=−0.32%/K) than the cell with Spiro-OMeTAD HTL (TC=−0.53%/K). The parameters that could improve the solar cell efficiency (η) obtained after these substitutions were also optimized. In particular, the parameters of the Sb2S3 absorber layer (thickness, defect density, and doping), ETL and HTL layer thicknesses, h-ETL/Sb2S3 interface defect density, and series and shunt resistances have been optimized. Finally, by combining high performance and thermal stability, the results show that the thermal stability of the solar cell depends on the back contact type; thus, nickel (Ni) was found to combine high performance and better thermal stability among the back contacts investigated. After these improvements, the efficiency of the Sb2S3-based solar cell increased from 5.08% (JSC=16.19 mA/cm2, VOC=0.56 V, and FF=55.40%) to 15.43% (JSC=18.51 mA/cm2, VOC=1.11 V, and FF=74.76%). This study proposes an approach to optimize the Sb2S3 upper subcell for tandem solar cells.

Modeling a tandem solar cell based on Sb2S3 and Sb2Se3 absorber layers

A device simulation presented for a tandem solar cell of Sb2S3 and Sb2Se3 as top (Eg = 1.7 eV) and bottom (Eg = 1.2 eV) absorber layers. We examined the device characteristics, radiative recombination, and optimum thickness of this tandem cell using filtered spectrum analysis and current-matching techniques in COMSOL. An open-circuit voltage of 1.58 V, current density of 15.50 mA/cm−2, fill factor of 56.90 %, and a remarkable efficiency of 14 %. The optimum thickness of Sb2S3 is 350 nm and for Sb2Se3 is 760 nm. Promising characteristics obtained with a Jsc = 16.32 mA/cm2, Voc = 1.48 V, FF = 60.7 %, and an overall power conversion efficiency of 14.66 %. The optimum acceptor and bulk defect density have been calculated to be NA = 8.9 × 1015 cm−3 and BDD = 7.21 × 10−15 cm−3. The optimized values of radiative recombination rate in Sb2S3 and Sb2Se3 are 0.73 × 10−10 cm3/s and 6.5 × 10−11 cm3/s, respectively.

Realization of High Photovoltaic Efficiency Devices With Sb₂S₃ Absorber Layer

Realization of High Photovoltaic Efficiency Devices With Sb₂S₃ Absorber Layer

Solution-Processed Sb2S3-Based Heterojunction for Self-Powered Broad Band Weak Light Detection.

Antimony sulfide (Sb2S3) has recently regained the attention of photovoltaic researchers as a promising solar absorber; however, its application for the detection of white light remains relatively unexplored. Herein, we report on the self-powered heterojunction photodetector based on a device-grade Sb2S3 film made at low temperature with solution processing. The Sb2S3 absorber film was prepared by single-step spin coating of a novel precursor ink using antimony trichloride as the antimony source along with the low melting thioacetamide as the sulfur source in 2-methoxyethanol, a low boiling environmentally friendly solvent. A simple TiO2/Sb2S3 heterojunction device made by using the film shows a power conversion efficiency of 1.22% without any hole transporting layer. Interestingly, the self-powered photodetector performance of the device under white light exhibits a high on/off ratio of 2.2 × 104 under 1 sun illumination. Moreover, this optical filter-free ultraviolet-visible absorbing near-infrared blind photodetector is equally capable of detecting both strong and weak white light, with a response time of 98 ms. Further, an example of the real-life application of the device is successfully demonstrated by constructing a weak light-detecting sunlight tracking system.

Fluorene- and fluorenone-based molecules as electron-transporting SAMs for photovoltaic devices.

New semiconductors containing fluorene or fluorenone central fragments along with phosphonic acid anchoring groups were synthesized and investigated as electron transporting materials for possible application in photovoltaic devices. These derivatives demonstrate good thermal stability and suitable electrochemical properties for effective electron transport from perovskite, Sb2S3 and Sb2Se3 absorber layers. Self-assembled fluorene and fluorenone electron-transporting materials have shown improved substrate wettability, indicating bond formation between monolayer-forming compounds and the ITO, TiO2, Sb2S3, or Sb2Se3 surface. Additionally, investigated materials have compatible energetic band alignment and can passivate perovskite interface defects, which makes them interesting candidates for application in the n-i-p structure perovskite solar cell.

Dopant-free fluorene based dimers linked with thiophene units as prospective hole transport materials for Sb2S3 solar cells

Novel dopant-free dimers comprising methoxydiphenylamine substituted fluorene derivatives as hole transport materials (HTMs) in Sb2S3 absorber solar cells.

Spectrum splitting approach based design simulation for multilayer chalcogenide solar cell architecture

We report design simulation on multilayer solar cell architecture aimed at enhancing the absorption efficiency in antimony sulfide (Sb2S3) absorber based cell via spectrum splitting approach. The poor experimental efficiency chalcogenide absorber (say; ∼8% for Sb2S3) based solar cell has been attributed to inadequate rear contact barrier, a high concentration of point defects (both acceptor and donor) within the bulk, low carrier lifetime, and the presence of defects at the absorber/buffer interface. A hetero-structure design modification vis-à-vis experimental report using bandgap tunability of Sb2S3 via point-focusing spectral splitting technique approach has been implemented to upscale the efficiency. The incident solar spectrum has been split into three well defined regimes for a focussed bandgap matching to enable light absorption and minimize transmission and thermalization losses. The adopted point-focusing spectral splitting technique in this work has resulted in an efficiency of 18.0%, which is an advancement by 2.25 times over the highest reported efficiency of 8.0% in the literature for Sb2S3 absorber based solar cells.

Grain Engineering of Sb2 S3 Thin Films to Enable Efficient Planar Solar Cells with High Open-Circuit Voltage.

Sb2 S3 is a promising environmentally friendly semiconductor for high performance solar cells. But, like many other polycrystalline materials, Sb2 S3 is limited by nonradiative recombination and carrier scattering by grain boundaries (GBs). This work shows how the GB density in Sb2 S3 films can be significantly reduced from 1068±40to 327±23nm µm-2 by incorporating an appropriate amount of Ce3+ into the precursor solution for Sb2 S3 deposition. Through extensive characterization of structural, morphological, and optoelectronic properties, complemented with computations, it is revealed that a critical factor is the formation of an ultrathin Ce2 S3 layer at the CdS/Sb2 S3 interface, which can reduce the interfacial energy and increase the adhesion work between Sb2 S3 and the substrate to encourage heterogeneous nucleation of Sb2 S3 , as well as promote lateral grain growth. Through reductions in nonradiative recombination at GBs and/or the CdS/Sb2 S3 heterointerface, as well as improved charge-carrier transport properties at the heterojunction, this work achieves high performance Sb2 S3 solar cells with a power conversion efficiency reaching 7.66%. An impressive open-circuit voltage (VOC ) of 796mV is achieved, which is the highest reported thus far for Sb2 S3 solar cells. This work provides a strategy to simultaneously regulate the nucleation and growth of Sb2 S3 absorber films for enhanced device performance.

Sb2S3 Thin-Film Solar Cells Fabricated from an Antimony Ethyl Xanthate Based Precursor in Air.

The rapidly expanding demand for photovoltaics (PVs) requires stable, quick, and easy to manufacture solar cells based on socioeconomically and ecologically viable earth-abundant resources. Sb2S3 has been a potential candidate for solar PVs and the efficiency of planar Sb2S3 thin-film solar cells has witnessed a reasonable rise from 5.77% in 2014 to 8% in 2022. Herein, the aim is to bring new insight into Sb2S3 solar cell research by investigating how the bulk and surface properties of the Sb2S3 absorber and the current-voltage and deep-level defect characteristics of solar cells based on these films are affected by the ultrasonic spray pyrolysis deposition temperature and the molar ratio of thiourea to SbEX in solution. The properties of the Sb2S3 absorber are characterized by bulk- and surface-sensitive methods. Solar cells are characterized by temperature-dependent current-voltage, external quantum efficiency, and deep-level transient spectroscopy measurements. In this paper, the first thin-film solar cells based on a planar Sb2S3 absorber grown from antimony ethyl xanthate (SbEX) by ultrasonic spray pyrolysis in air are demonstrated. Devices based on the Sb2S3 absorber grown at 200 °C, especially from a solution of thiourea and SbEX in a molar ratio of 4.5, perform the best by virtue of suppressed surface oxidation of Sb2S3, favorable band alignment, Sb-vacancy concentration, a continuous film morphology, and a suitable film thickness of 75 nm, achieving up to 4.1% power conversion efficiency, which is the best efficiency to date for planar Sb2S3 solar cells grown from xanthate-based precursors. Our findings highlight the importance of developing synthesis conditions to achieve the best solar cell device performance for an Sb2S3 absorber layer pertaining to the chosen deposition method, experimental setup, and precursors.

Space-Charging Interfacial Layer by Illumination for Efficient Sb2S3 Bulk-Heterojunction Solar Cells with High Open-Circuit Voltage

Solution-processed material systems for effective photovoltaic conversion are the key to low-cost and efficient solar cells. While antimony trisulfide (Sb2S3) is a promising photovoltaic absorber, solution-processed quality Sb2S3-based heterojunction systems for solar cells, particularly with an open-circuit voltage (Voc) higher than 0.70 V, are challenging issues. Here, a cadmium sulfide (CdS) interfacial engineering method is developed for the Sb2S3-based bulk-heterojunction (BHJ) solar cells with an efficiency of 6.14% and a Voc up to 0.76 V that is the highest one among solution-processed Sb2S3 solar cells. The prepared Sb2S3-based BHJ solar cells feature a Sb2S3 nanoparticle film interdigitated by a titania (TiO2) nanorod array with a nanostructured CdS shell as an interfacial layer on each TiO2 nanorod core. Upon understanding the interfacial interactions and band alignments in the TiO2-CdS-Sb2S3 system, the function of the CdS interfacial layer as a band-bended spatial spacer interacting strongly with both the TiO2 electron transporter and Sb2S3 absorber for increasing charge collecting efficiency is revealed; moreover, space-charging the band-bended CdS layer by illumination is found and a photogenerated interfacial dipole electric field model is proposed for understanding the high Voc subjected to the presence of the CdS interfacial layer. This work provides a conceptual guide for designing efficient inorganic heterojunction solar cells.

Effect of design modification on efficiency enhancement in Sb2S3 absorber based solar cell

Effect of design modification on efficiency enhancement in Sb2S3 absorber based solar cell

Design simulation analysis for large enhancement in efficiency of sulphur substituted Sb2S3 absorber based solar cell

We report, two stage simulation analysis on optimization of materials and design parameters of earth abundant cost-effective chalcogenide absorber, Sb2S3, based solar cell. Large enhancement in the efficiency is achieved when sulphur is selectively substituted by Se. The 1st level of simulation aimed at analyzing the effect of partial sulphur replacement by Se in Sb2S3 to achieve; (i) desirable band gap tailoring in Sb2(S1−xSex)3, (ii) optimal conditions to strike out an optimal value for both VOC and JSC, (iii) enhanced absorption limit in the UV-Visible spectrum, (iv) improved back contact controlling the losses. It resulted in efficiency enhancement as high as 83% to the tune of 13.86% for Sb2(S½Se½)3 when compared to that of 7.5% for Sb2S3 solar cell. In the 2nd stage of simulation for design optimization, we addressed the prime design issues pertaining to (a) absorber layer thickness, (b) absorber defect density and (c) back-contact work function. Consequently, an additional efficiency enhancement ∼ 45% occurred from 13.86% to 20.15%. The results suggest feasibility of earth abundant absorber component Sb2(S, Se)3 based cost effective solar cell. This work provides a potential avenue for experimentalists to implement in experiments since simulation prediction agreed well with preliminary experimental results.

Numerical Simulation of Non-toxic ZnSe Buffer Layer to Enhance Sb2S3 Solar Cell Efficiency Using SCAPS-1D Software

The use of renewable energy, especially solar photovoltaic, has grown more and more necessary in the context of the diversification of the use of natural resources. Sb2S3 is emerged as an attractive candidate for today's thin-film solar cells due to its band gap of 1.65 eV and high absorption coefficient greater than 105 cm-1. Cadmium Sulfide is the most commonly used buffer layer material in thin film solar cells, but cadmium is a metal that causes severe toxicity in humans and the environment. This article tried to avoid cadmium for solar cell generation. This paper presents the findings of a computer simulation analysis of a thin film solar cell based on a p-type Sb2S3 absorber layer and an n-type ZnSe buffer layer in a structure of (Sb2S3/ZnSe/i-ZnO/ZnO: Al) utilizing simulation software (SCAPS-1D). The simulation included detailed configuration optimization for the thickness of the absorber layer, buffer layer, defect density, temperature, and series-shunt resistance. In this work, the Efficiency (η), Fill Factor (FF), Open-circuit Voltage (Voc), and short-circuit current (Jsc) have been measured by varying thickness of absorber layer in the range of 0.5µm to 4 µm and by varying thickness of buffer layer in the range of 0.05 µm to 0.1µm. The optimized solar cell shows an efficiency of 20.03% when the absorber layer thickness is 4µm and the buffer layer thickness is 0.08µm.

Concurrent investigation of antimony chalcogenide (Sb2Se3 and Sb2S3)-based solar cells with a potential WS2 electron transport layer

Antimony (Sb) chalcogenides such as antimony selenide (Sb2Se3) and antimony sulfide (Sb2S3) have distinct properties to be used as absorber semiconductors for harnessing solar energy including high absorption coefficient, tunable bandgap, low toxicity, phase stability. The potentiality of Sb2Se3 and Sb2S3 as absorber material in Al/FTO/Sb2Se3(or Sb2S3)/Au heterojunction solar cells (HJSCs) with 2D tungsten disulfide (WS2) electron transport layer (ETL) layer has been investigated numerically using SCAPS-1D solar simulator. A systematic investigation of the impact of physical properties of each active material of Sb2Se3, Sb2S3, and WS2 on photovoltaic parameters including layer thickness, carrier doping concentration, bulk defect density, interface defect density, carrier generation, and recombination. This study emphasizes the exploration of causes of low performance of actual devices and demonstrates the individual variation in the open-circuit voltage (VOC), short-circuit current density (JSC), fill factor (FF), power conversion efficiency (PCE) and quantum efficiency (QE). Thereby, highly potential heterostructures of Al/FTO/WS2/absorber (Sb2Se3 or Sb2S3)/Au proposed, in which, the PCE over 28.20 and 26.60% obtained with VOC of 850 and 1230 mV, Jsc of 38.0 and 24.0 mA/cm2, and FF of 86.0 and 89.0% for Sb2Se3 and Sb2S3 absorber, respectively. These detailed findings revealed that the Sb-chalcogenide heterostructure with potential WS2 ETL can be used to realize the fabrication of feasible thin film solar cells and thus the design of high-efficiency high-current (HEHC) and high-efficiency high-voltage (HEHV) solar panels.

A Codoping Strategy for Efficient Planar Heterojunction Sb2S3 Solar Cells

AbstractAntimony sulfide is a promising wide bandgap light‐harvesting material owing to its high absorption coefficient, nontoxicity, superior stability, and low cost. However, the reported Sb2S3 absorber suffers from complicated defect characteristics due to its quasi‐1D structure. Herein, a codoping technique from chlorine and selenium is developed in hydrothermal method to regulate the film defect properties and promote the device efficiency. The theoretical calculation and experimental results demonstrate that the Cl&Se codoping plays a synergistic role in absorber film quality improvement. Se doping could efficiently fill the intrinsic deep defect level VS and Cl is a benign n‐type dopant and favor [hk1] oriented deposition. Systematic device physical characterizations verify the codoped device superior heterojunction quality and much lower interface and bulk defect density comparing with control one. The optimal codoping device delivers a certified power conversion efficiency of 7.15% (5.9% for control one), the highest certified value in planar Sb2S3 solar cells. This study develops an effective doping strategy with multi‐element synergistic incorporation which sheds new light on high‐efficiency Sb2S3 solar cells.

Atomic-layer-deposited TiO2 and SnO2 coupled with CdS as double buffer layers for HTL-free Sb2S3 thin-film solar cells

The application of double buffer layers has been proven to be a beneficial approach for the enhancement of the power conversion efficiency (PCE) of antimony sulfide (Sb2S3) thin-film solar cells (TFSCs). Recently, solution-processed SnO2/CdS, TiO2/CdS, ZnMgO/CdS, and ZnSnO/CdS electron transport layers (ETLs) have been investigated as double buffer layers for Sb2S3 TFSCs. Herein, atomic-layer-deposited (ALD) SnO2 and TiO2 ETLs were applied as a double buffer layer with CdS for Sb2S3 TFSCs. The Sb2S3 absorber was deposited using a facile hydrothermal method. The TFSC devices were fabricated based on FTO/SnO2/CdS/Sb2S3/Au or FTO/TiO2/CdS/Sb2S3/Au structure without hole transport layers (HTLs). Experimental analysis revealed the reduction of the surface roughness of ETLs and decreased unfavorable (hk0) orientation of the Sb2S3 absorber after utilizing double buffer layers. Initially, incomplete nucleation of Sb2S3 was observed on SnO2 and TiO2 ETLs, which resulted in the formation of a shunting path. Conversely, complete nucleation of Sb2S3 was observed on CdS and double buffer layers. The highest PCEs of 3.98% and 4.23% were obtained for SnO2/CdS and TiO2/CdS double-buffer-layer-based cells with improvements exceeding 1% compared with the reference CdS buffer layer. Additionally, improvements in open-circuit voltage (VOC) of the order of ∼25 mV and ∼45 mV were respectively observed for SnO2/CdS (VOC = 0.676 V) and TiO2/CdS (VOC = 0.696 V) double-buffer-layer-based devices compared with the reference CdS buffer layer (VOC = 0.648 V). The enhanced device properties are mainly attributed to the improved charge carrier collection and formation of suitable band offset at the absorber and ETLs interfaces.