Sb2S3 Solar Cells Research Articles

Enhanced Performance of Close-Spaced Sublimation Processed Antimony Sulfide Solar Cells via Seed-Mediated Growth.

Antimony sulfide (Sb2S3) has attracted much attention due to its great prospect to construct highly efficient, cost-effective, and environment-friendly solar cells. The scalable close-spaced sublimation (CSS) is a well-developed physical deposition method to fabricate thin films for photovoltaics. However, the CSS-processed absorber films typically involve small grain size with high-density grain boundaries (GBs), resulting in severe defects-induced charge-carrier nonradiative recombination and further large open-circuit voltage (VOC) losses. In this work, it is demonstrated that a chemical bath deposited-Sb2S3 seed layer can serve as crystal nuclei and mediate the growth of large-grained, highly compact CSS-processed Sb2S3 films. This seed-mediated Sb2S3 film affords reduced defect density and enhanced charge-carrier transport, which yields an improved power conversion efficiency (PCE) of 4.78% for planar Sb2S3 solar cells. Moreover, the VOC of 0.755V that is obtained is the highest reported thus far for vacuum-based evaporation and sublimation processed Sb2S3 devices. This work demonstrates an effective strategy to deposit high-quality low-defect-density Sb2S3 films via vacuum-based physical methods for optoelectronic applications.

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.

Surface treatment processed electron transport layers for efficient Sb2S3 solar cells

Solution-processed Sb2S3 thin films and solar cell devices have recently gained popularity due to their easy procedure and outstanding final device performance. Nevertheless, although the substrate has a significant influence on thefollowing functional films, the effect of the substrate in the Sb-based solar cells appears to have not been adequately examined. In this study, we performed an interesting thioacetamide (TA)-assisted surface treatment strategy on the electron transport layer (ETL) to achieve high-quality development of Sb2S3 thin films and based solar devices. The surface treatment of ETLs resulted in a uniform surface, Zn(OH)2 impurity reduction, and excellent wettability. The above enhanced the growth of Sb2S3 thin films with features like extremely large crystal sizes (∼8 um), more homogeneous and dense film morphology, preferred crystal orientation, reduced oxygen content, and fewer defects, which benefits carrier transport. Finally, a device structure constructed of FTO/TiO2/Zn(O,S)/Sb2S3/Spiro/Au was created, resulting in an almost 30 % increase in efficiency, from 4.05 % to 5.21 %. The proposed approach not only gives new insights into generating higher-quality Sb2S3 thin films and devices, but it also presents new concepts and methods for future high-quality sulfide thin film preparation.

Modifying back contact by silver to Enhance the performance of carbon-based Sb2S3 solar cells

Antimony sulfide (Sb2S3) has drawn significant attention due to its excellent photoelectric properties. However, the photon conversion efficiency of Sb2S3 solar cell is limited by its magnificent value band offset between absorber layer and carbon electrode. Herein, a back surface optimization strategy is developed to reduce the barrier at the back contact. By introducing Ag at back contact before post-selenization process, the Valence-Band Maximum (VBM) of Sb2S3 is elevated under the action of spin–orbit interaction between Sb-5 s orbit and Ag-d orbit, leading to improve the extraction of holes. Consequently, the electrical conductivity of the film undergoes a significant improvement, rising from 1.20 × 10-5 to 1.59 × 10-5 S/cm. Additionally, the film surface morphology is refined, exhibiting a reduction in roughness from 17.1 nm to 13.6 nm, which leads to less leak current generated. Finally, the device based on FTO/SnO2/CdS/Sb2S3/Carbon structure achieved the power conversion efficiency (PCE) of 5.51 %, representing a 16 % improvement compared to the device without Ag treatment.

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.

Self‐Regulated Growth of Large‐Grain Sb2S3 Thin Films for High‐Efficiency Solar Cells

AbstractAntimony sulfide (Sb2S3) has attracted extensive attention due to its excellent photoelectric characteristics, including a high absorption coefficient (α > 104 cm−1) and a suitable bandgap (≈1.7 eV). However, due to its Q1D (quasi‐1D) structure, numerous deep‐level defects are identified in the Sb2S3 film, limiting the device's performance, and necessitating more efforts to overcome this situation. In this context, an ethanol solvent‐assisted chemical bath deposition (S‐CBD) strategy, a novel high‐quality thin film manufacturing technique is presented that modifies the supersaturation of the precursor solution by varying the boiling point and solvent polarity. This approach enables the effective regulation of the correlation between the crystal nucleation and growth rates, resulting in Sb2S3 films with large grains (≈4.25 µm, 37.5% ethanol), excellent crystallinity, well‐oriented structures (TC(211)/TC(020) = 2.39), low defect density, and prolonged carrier lifetimes (τAve ≈ 12.1 ns). Consequently, the final Sb2S3‐based solar device (FTO/CdS/Sb2S3/Spiro‐OMeTAD/Au) shows significant improvements in both FF (61.63%) and JSC (17.61 mA cm−2), yielding an excellent power conversion efficiency (PCE) of 7.84%. This research gives particular insights into the growth mechanism of high‐quality Sb2S3 thin films by CBD method as well as a potential route for enhancing Sb2S3 solar cell performance.

Interfacial Engineering by Self‐Assembled Monolayer for High‐Performance Sb2S3 Solar Cells

AbstractAntimony chalcogenides films and devices have drawn much attention in recent years because of their notable advantages. Unfortunately, the performance of Sb‐based solar cells is still underdeveloped compared to the theoretical value, which is closely related to charge carrier separation and transfer, highlighting the importance of enhancing the interface quality. In this work, an interfacial engineering by utilizing a self‐assembled monolayer (SAM) of MeO‐2PACz as an interface layer between the Sb2S3 and Spiro‐OMeTAD is developed to assist hole transport. The strong interface interaction between Sb2S3 and MeO‐2PACz is systematically investigated by Raman, X‐ray photoelectron spectroscopy (XPS) measurements, and Density functional theory (DFT) calculations. Through such interfacial engineering, a more uniform surface potential, bigger built‐in potential, better energy‐level match as well as outstanding photoelectric properties are achieved. Finally, the champion power conversion efficiency (PCE = 8.06%) of Sb2S3 solar cells with SAMs is inspiringly enhanced by >13%. It is expected that this effort will bring fresh insights and strategies for improving the performance of Sb‐based solar devices.

Scrutinizing transport phenomena and recombination mechanisms in thin film Sb2S3 solar cells

The Schockley–Quisser (SQ) limit of 28.64% is distant from the Sb2S3 solar cells’ record power conversion efficiency (PCE), which is 8.00%. Such poor efficiency is mostly owing to substantial interface-induced recombination losses caused by defects at the interfaces and misaligned energy levels. The endeavor of this study is to investigate an efficient Sb2S3 solar cell structure via accurate analytical modeling. The proposed model considers different recombination mechanisms such as non-radiative recombination, Sb2S3/CdS interface recombination, Auger, SRH, tunneling-enhanced recombination, and their combined impact on solar cell performance. This model is verified against experimental work (Glass/ITO/CdS/Sb2S3/Au) where a good coincidence is achieved. Several parameters effects such as thickness, doping, electronic affinity, and bandgap are scrutinized. The effect of both bulk traps located in CdS and Sb2S3 on the electrical outputs of the solar cell is analyzed thoroughly. Besides, a deep insight into the effect of interfacial traps on solar cell figures of merits is gained through shedding light into their relation with carriers’ minority lifetime, diffusion length, and surface recombination velocity. Our research findings illuminate that the primary contributors to Sb2S3 degradation are interfacial traps and series resistance. Furthermore, achieving optimal band alignment by fine-tuning the electron affinity of CdS to create a Spike-like conformation is crucial for enhancing the immunity of the device versus the interfacial traps. In our study, the optimized solar cell configuration (Glass/ITO/CdS/Sb2S3/Au) demonstrates remarkable performance, including a high short-circuit current (JSC) of 47.9 mA/cm2, an open-circuit voltage (VOC) of 1.16 V, a fill factor (FF) of 54%, and a notable improvement in conversion efficiency by approximately 30% compared to conventional solar cells. Beyond its superior performance, the optimized Sb2S3 solar cell also exhibits enhanced reliability in mitigating interfacial traps at the CdS/Sb2S3 junction. This improved reliability can be attributed to our precise control of band alignment and the fine-tuning of influencing parameters.

Tri-chalcogenides (Sb2S3/Bi2S3) solar cells with double electron transport layers: design and simulation

To make technology accessible to everyone, it is essential to focus on affordability and durability of the devices. Antimony trisulfide (Sb2S3) and bismuth (III) sulfide (Bi2S3) are low-cost and stable materials that are commonly used in photovoltaic devices due to their non-toxic nature and abundance. These materials are particularly promising for photovoltaic applications as they are effective light-absorbing materials. In this study, we utilized the Solar cell Capacitance Simulator- One-Dimensional (SCAPS-1D) software to investigate the parameters of a double electron transport layer (ETL) solar cell based on Sb2S3/ Bi2S3. The parameters examined included thickness of the absorber layer, overall defect density, density of acceptors, radiative recombination coefficient, series and shunt resistance, and work function of the back contact. The solar cell structure studied was FTO/SnO2/CdS/ Sb2S3 and Bi2S3/Spiro-OMeTAD/Au. By incorporating a SnO2 electron transport layer (ETL) into the double ETL structure of Sb2S3 and Bi2S3 solar cells, we observed a significant enhancement in the power conversion efficiency (PCE). Specifically, the PCE increased to 19.71% for the Sb2S3 solar cell and 24.05% for the Bi2S3 solar cell. In contrast, without SnO2, the single ETL-based CdS solar cell achieved a maximum PCE of 18.27 and 23.05% for Sb2S3 and Bi2S3, respectively.

ZnxCd1–xSySe1–y as an effective electron transport layer for improving the efficiency of Sb2S3 and Sb2Se3 thin-film solar cells

ZnxCd1–xSySe1–y as an effective electron transport layer for improving the efficiency of Sb2S3 and Sb2Se3 thin-film solar cells

All-Inorganic Hydrothermally Processed Semitransparent Sb2S3 Solar Cells with CuSCN as the Hole Transport Layer.

An inorganic wide-bandgap hole transport layer (HTL), copper(I) thiocyanate (CuSCN), is employed in inorganic planar hydrothermally deposited Sb2S3 solar cells. With excellent hole transport properties and uniform compact morphology, the solution-processed CuSCN layer suppresses the leakage current and improves charge selectivity in an n-i-p-type solar cell structure. The device without the HTL (FTO/CdS/Sb2S3/Au) delivers a modest power conversion efficiency (PCE) of 1.54%, which increases to 2.46% with the introduction of CuSCN (FTO/CdS/Sb2S3/CuSCN/Au). This PCE is a significant improvement compared with the previous reports of planar Sb2S3 solar cells employing CuSCN. CuSCN is therefore a promising alternative to expensive and inherently unstable organic HTLs. In addition, CuSCN makes an excellent optically transparent (with average transmittance >90% in the visible region) and shunt-blocking HTL layer in pinhole-prone ultrathin (<100 nm) semitransparent absorber layers grown by green and facile hydrothermal deposition. A semitransparent device is fabricated using an ultrathin Au layer (∼10 nm) with a PCE of 2.13% and an average visible transmittance of 13.7%.

Understanding the effect of TiCl4 treatment at TiO2/Sb2S3 interface on the enhanced performance of Sb2S3 solar cells

The continuous search for low-cost and environment-friendly materials in photovoltaic applications has become a priority, as well as the understanding of the various strategies to boost the photovoltaic performance. In this work, we investigate the effect of TiCl4 treatment on a compact TiO2 layer used as an electron transport material (ETM) in Sb2S3 planar solar cells. After TiCl4 treatment, TiO2 exhibits higher crystallinity, lower density of hydroxyl groups acting as traps, and better surface coverage of the FTO substrate. Although no major structural changes are observed in Sb2S3 films grown on pristine or TiCl4 treated TiO2 films, there are differences in preferential growth of Sb2S3 (hk1) planes, sulfur-enrichment of the chalcogenide film, and superior substrate coverage after the TiCl4 treatment, leading to the decrease of interfacial trap states. The driving force for electron injection in the TiO2/Sb2S3 heterojunction is also favored by the shift on the VB and CB positions of TiCl4 treated TiO2. These findings are in agreement with the improved power conversion efficiency of the planar solar cell FTO/TiO2-Treated/Sb2S3/SbCl3/spiro-OMeTAD/Au.

Recent Advances and Prospects of Solution‐Processed Efficient Sb2S3 Solar Cells

AbstractSolar cells comprising earth‐abundant and non‐toxic elements with applicable bandgaps and high absorption coefficients have attracted considerable interest over the past several decades and are important devices for addressing the future demand for clean and renewable energy. Antimony sulfide (Sb2S3) crystal material effectively meets these requirements owing to its suitable bandgap, high absorption coefficient, high electron and hole mobilities, earth abundance, and excellent stability. Solution‐processed Sb2S3 films are essential to facilitate the fabrication of low‐cost, large‐scale, and high‐efficiency photovoltaic devices, but suffer from several shortcomings of large intrinsic defects, high interfacial barrier, and atomic mismatch, uncontrollable film thickness, and crystal orientation. In this review, a systematic overview of the fundamental properties of solution‐processed Sb2S3 materials is presented, and then interface engineering, defect passivation and control strategies, crystal orientation and modulation methods, device structure, and the performance of Sb2S3 solar cells are focused, highlighting the primary advancements and major challenges based on this technology. Finally, several creative perspectives and constructive innovation strategies for future research on Sb2S3 photovoltaic devices are provided, indicating a roadmap for the practical application of other inorganic semiconductor heterojunction thin film solar cells.

CdS-carbon black hybrid nanocomposite buffer layer for antimony sulfide solar cells

A novel hybrid nanocomposite based on CdS and carbon nanoparticles used as a buffer layer in Sb2S3 solar cells improved the charge transfer and interfacial quality junction, which enhances the photovoltaic performance.

Optical loss analysis of Sb2S3 and Sb2Se3 thin film solar cells: A Quantitative Assessment

Optical loss either by light reflection, or light absorption in different layers of a solar cell, can significantly impact short-circuit current density. In this paper, an optical model has been developed to analyze the optical loss in thin film solar cells made of CdS/Sb2S3 or CdS/Sb2Se3 antimony chalcogenide. This model is based on optical loss from absorption in thin layers and reflection at the interfaces of glass/TCO/CdS/(Sb2S3 or Sb2Se3) only by considering the optical properties of layers (refractive index and extinction coefficient). The transmission and reflection rate of Sb2S3 or Sb2Se3 show almost a similar trend. The absorptivity and relative loss in short-circuit current density (Jsc) versus the thickness of Sb2S3 and Sb2Se3 layers was calculated for two different structures: glass/TCO/CdS/Sb2S3 and glass/TCO/CdS/Sb2Se3. The Sb2Se3 solar cell shows a slightly better conversion performance compared to Sb2S3 solar cell due to lower reflection loss. The light reflection was calculated at four interfaces. The transmission rate of light through TCO, ITO, and CdS layers was calculated to obtain an optimal thickness for these layers. TCO showed a higher transmission rate and thus is preferred in antimony solar cell structures. The variations of (Jsc) and loss for Jsc with different thicknesses of ITO (>20%) or TCO (<20%) contact layers, favoring TCO for its lower optical losses and higher Jsc (24 mA cm−2).

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.

Self-assembled growth of quasi-vertically oriented Sb2S3 thin films for substrate structured solar cells

Antimony sulfide (Sb2S3) is an appealing one-dimensional light-harvesting material for thin-film solar cells due to the high absorption coefficient, suitable bandgap and abundance of constituent elements. The orientation of the Sb2S3 thin film is considered as one of the most important factors affecting the performance of the device. According to the minimum energy principle, Sb2S3 is prone to grow parallel to the substrate along the [hk0] orientation which is harmful to the device performance. On the other hand, [hk1]-oriented films are much more beneficial but additional processes such as annealing are often required. In this work, stoichiometric Sb2S3 thin films consist of compact, highly [hk1]-oriented grains have been prepared via a self-assembled growth by magnetron sputtering and post-sulfurization. After carefully optimized the preparation process, a champion device (2.89% power conversion efficiency) was obtained with an open-circuit voltage of 696 mV and a short-circuit current density of 12.48 mA/cm2 under AM 1.5G solar radiation. Interestingly, the high open-circuit voltage of our device is already comparable to the state-of-the-art Sb2S3 solar cells. This work demonstrates a great potential of the sputtering and post-sulfurization method in fabrication of high-efficiency substrate Sb2S3 thin-film solar cells.

Parallel Planar Heterojunction Strategy Enables Sb2S3 Solar Cells with Efficiency Exceeding 8 %

AbstractSolution‐processed solar cells based on inorganic heterojunctions provide a potential approach to the efficient, stable and low‐cost solar cells required for the terrestrial generation of photovoltaic energy. Antimony trisulfide (Sb2S3) is a promising photovoltaic absorber. Here, an easily solution‐processed parallel planar heterojunction (PPHJ) strategy and related principle are developed to prepare efficient multiple planar heterojunction (PHJ) solar cells, and the PPHJ strategy boosts the efficiency of solution‐processed Sb2S3 solar cells up to 8.32 % that is the highest amongst Sb2S3 devices. The Sb2S3‐based PPHJ device consists of two kinds of conventional planar heterojunction (PHJ) subcells in a parallel connection: Sb2S3‐based PHJ subcells dominating the absorption and charge generation and CH3NH3PbI3‐based PHJ subcells governing the electron transport towards collection electrode, but it belongs to an Sb2S3 device in nature. The resulting PPHJ device combines together the distinctive structural features of Sb2S3 absorbing layer as a main absorber and the duplexity of well‐crystallized/oriented CH3NH3PbI3 layer in charge transportation as an additional absorber, while the presence of perovskite does not affect device stability. The PPHJ strategy maintains the facile preparation by the conventional sequential depositions of multiple layers, but eliminates the normal complexity in both tandem and parallel tandem PHJ systems.

Parallel Planar Heterojunction Strategy Enables Sb2 S3 Solar Cells with Efficiency Exceeding 8 .

Solution-processed solar cells based on inorganic heterojunctions provide a potential approach to the efficient, stable and low-cost solar cells required for the terrestrial generation of photovoltaic energy. Antimony trisulfide (Sb2 S3 ) is a promising photovoltaic absorber. Here, an easily solution-processed parallel planar heterojunction (PPHJ) strategy and related principle are developed to prepare efficient multiple planar heterojunction (PHJ) solar cells, and the PPHJ strategy boosts the efficiency of solution-processed Sb2 S3 solar cells up to 8.32 % that is the highest amongst Sb2 S3 devices. The Sb2 S3 -based PPHJ device consists of two kinds of conventional planar heterojunction (PHJ) subcells in a parallel connection: Sb2 S3 -based PHJ subcells dominating the absorption and charge generation and CH3 NH3 PbI3 -based PHJ subcells governing the electron transport towards collection electrode, but it belongs to an Sb2 S3 device in nature. The resulting PPHJ device combines together the distinctive structural features of Sb2 S3 absorbing layer as a main absorber and the duplexity of well-crystallized/oriented CH3 NH3 PbI3 layer in charge transportation as an additional absorber, while the presence of perovskite does not affect device stability. The PPHJ strategy maintains the facile preparation by the conventional sequential depositions of multiple layers, but eliminates the normal complexity in both tandem and parallel tandem PHJ systems.

Precursor Engineering of Solution-Processed Sb2 S3 Solar Cells.

Antimony-based chalcogenides have emerged as promising candidates for next-generation thin film photovoltaics. Particularly, binary Sb2 S3 thin films have exhibited great potential for optoelectronic applications, due to the facile and low-cost fabrication, simple composition, decent charge transport and superior stability. However, most of the reported efficient Sb2 S3 solar cells are realized based on chemical bath deposition and hydrothermal methods, which require large amount of solution and are normally very time-consuming. In this work, Ag ions are introduced within the Sb2 S3 sol-gel precursors, and effectively modulated the crystallization and charge transport properties of Sb2 S3 . The crystallinity of the Sb2 S3 crystal grains are enhanced and the charge carrier mobility is increased, which resulted improved charge collection efficiency and reduced charge recombination losses, reflected by the greatly improved fill factor and open-circuit voltage of the Ag incorporated Sb2 S3 solar cells. The champion devices reached a record high power conversion efficiency of 7.73% (with antireflection coating), which is comparable with the best photovoltaic performance of Sb2 S3 solar cells achieved based on chemical bath deposition and hydrothermal techniques, and pave the great avenue for next-generation solution-processed photovoltaics.