Sb2S3 Solar Cells Research Articles

Theoretical Analysis and Development of Multilayered Ecofriendly Sb2S3‐Based Solar Cell Using SCAPS‐1D Framework

Herein, FTO/TiO2/Sb2S3/Au solar cell characteristics via SCAPS‐1D modeling are examined. The research begins with device modeling of the Sb2S3 conventional solar cell based on experimental data, which results in excellent agreement with the power conversion efficiency recorded in the literature of ≈4.72%. The influence of several factors on the characteristics of conventional solar cells is then investigated, including Sb2S3 thickness, carrier concentration, bulk and interface defects, and buffer layer type (TiO2, WS2, and CdS). An optimal efficiency of 9.97%, open‐circuit voltage (Voc) of 0.96 V, short‐circuit current (Jsc) of 19.69%, and fill factor (FF) of 52.26% are found for the FTO/WS2/Sb2S3/Au optimized solar cell. Finally, the influence of NiO as the back surface field and parasitic resistance (Rs and Rsh) on the performance of Sb2S3 solar cells is investigated. The innovative solar cell design (FTO/WS2/Sb2S3/NiO/Au) with NiO thickness of 20 nm, Rs < 2 Ω cm−2, and Rsh > 700 Ω cm−2 yields a high efficiency of more than 14.38%, FF > 68.93%, Voc > 1 V, and Jsc > 20.67 mA cm−2. These qualities allow for the large‐scale manufacture of a solar cell by including it in a manufacturing workflow.

Effect of the Thickness and Sb–O Content in Sb2S3 Thin Films to the Solar Cell Efficiency

Herein, Sb2S3 thin films are successfully prepared by hydrothermal method using the mixing solution of SbCl3 and sodium citrate as a novel Sb source. The influence of the growth temperature and time, growth solution volume on the properties of Sb2S3 thin films, and the photovoltaic performance of the corresponding solar cells is systematically investigated. The results reveal that the thickness and Sb–O content in Sb2S3 thin films decrease with the increase of the growth temperature and growth solution volume and decrease of the growth time. When the chemical composition and volume of the growth solution are 120 mM SbCl3, 276 mM sodium citrate, 180 mM Na2S2O3, 60 mM thioacetamide, and 28 mL, and the growth temperature and time are 150 °C and 2 h, the thickness and molar ratios of Sb–O:Sb–S/O in Sb2S3 thin films are 295 nm and 0.14 and the corresponding solar cells achieve the power conversion efficiency (PCE) of 7.36%, which is the highest PCE in Sb2S3 solar cells using hydrothermal method. Therefore, the effect of the growth temperature and time, specially the growth solution volume, on the thickness and Sb–O content in Sb2S3 thin films is important for improving the PCE of Sb2S3 solar cells.

Sputtering of Molybdenum as a Promising Back Electrode Candidate for Superstrate Structured Sb2 S3 Solar Cells.

Sb2 S3 is rapidly developed as light absorber material for solar cells due to its excellent photoelectric properties. However, the use of the organic hole transport layer of Spiro-OMeTAD and gold (Au) in Sb2 S3 solar cells imposes serious problems in stability and cost. In this work, low-cost molybdenum (Mo) prepared by magnetron sputtering is demonstrated to serve as a back electrode in superstrate structured Sb2 S3 solar cells for the first time. And a multifunctional layer of Se is inserted between Sb2 S3 /Mo interface by evaporation, which plays vital roles as: i) soft loading of high-energy Mo particles with the help of cottonlike-Se layer; ii) formation of surficial Sb2 Se3 on Sb2 S3 layer, and then reducing hole transportation barrier. To further alleviate the roll-over effect, a pre-selenide Mo target and consequentially form a MoSe2 is skillfully sputtered, which is expected to manipulate the band alignment and render an enhanced holes extraction. Impressively, the device with an optimized Mo electrode achieves an efficiency of 5.1%, which is one of the highest values among non-noble metal electrode based Sb2 S3 solar cells. This work sheds light on the potential development of low-cost metal electrodes for superstrate Sb2 S3 devices by carefully designing the back contact interface.

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.

Bulk Defect Passivation for Full‐Inorganic Sb2S3 Solar Cells by Sulfur‐Atmosphere Recrystallization Process

Antimony sulfide (Sb2S3) solar cells have attracted extensive attention in silicon‐based tandem solar cells. The performance of Sb2S3 devices fabricated by the vacuum method is limited by sulfur vacancies (VS) and surface oxide defects during high‐temperature processes. Herein, amorphous Sb2S3 film based on low‐temperature rapid thermal evaporation (RTE) technique is fabricated to overcome S loss. Moreover, a sulfur‐atmosphere recrystallization strategy is further developed to obtain high‐quality absorbers from the amorphous film. The element content of Sb2S3 film is completely in accord with the stoichiometric ratio (2:3), and the surface oxides are effectively suppressed, enhancing VOC and fill factor. Compared to the control directly crystallized film, the defect concentrations of the S‐recrystallized Sb2S3 film are reduced by 61%, exhibiting better uniformity and higher PN junction quality. Ultimately, the full‐inorganic Sb2S3 solar cells (FTO/TiO2/Sb2S3/Au) achieve an efficiency of 6.25%. The S‐atmosphere recrystallization process can effectively passivate bulk defects (VS and Sb2O3) and suppress recombination to improve device performance, which will provide new prospects for vacuum method‐based Sb2S3 thin film solar cells.

Self-passivated CdS buffer layer for antimony sulfide solar cells

Sb2S3 has been paid extensive attentions as absorber for solar cells. Comparing with some oxides, CdS exhibits excellent compatibility to Sb2S3 therefore is most commonly used as buffer layer (BL) materials for Sb2S3 solar cells. Proper passivation can enhance the performance of CdS buffer layer thus raising the performances of Sb2S3 solar cells. Herein, we put forward a self-passivation strategy to enhance the performance of CdS by a two-step deposition process to fabricate the self-passivated CdS BL. First, we adopted spin coating combined with annealing process to prepare flaked CdS on FTO, then we performed passivation process to the CdS by depositing another layer of CdS with chemical bath deposition (CBD) method. After Sb2S3 was deposited on the self-passivated CdS by hydrothermal method, a solar cell with FTO/CdS (∼90 nm)/Sb2S3 (160 nm)/Spiro-OMeTAD(48 nm)/Ag(32 nm)structure was obtained by deposition of hole transport layer and Ag electrodes. Comparing with the single spin-coating processed CdS BL or single chemical bath deposited CdS BL, the self-passivated CdS presents better performance. The CBD process presents distinctive passivation effects to the first layer. In consequence, we obtained the highest PCE of 6.04 % in the Sb2S3 solar cells on the self-passivated CdS BL. The present work supplies a unique route to enhance the performances of CdS buffer layer.

A bithiophene-cored interfacial passivating layer for Sb2S3 solar cells with 7.1% efficiency

Sb2S3, which is an excellent performance of the third generation of solar cells with superior photovoltaic properties, high stability and environmental friendliness. However, because of the low formation energies of the cation-replaced-anion antisites and anion vacancies, the presence of these trap states result in increased unpaired Sb atoms, which could serve as charge recombination centers on the surface and grain boundaries. Here, we introduce a bithiophene-cored compound (BTR-TPA, 4,4'-([2,2′-bithiophene]-5,5′-diyl)bis(N,N-bis(4-methoxyphenyl)aniline)) as an interlayer between the Sb2S3 and hole transport layers to passivate the trap states. Suitable energy levels, inhibited antimony oxide impurity phase, low trap states together with remarkable photoelectric properties are obtained via introducing such an interface layer. As a result, the optimal power conversion efficiency (PCE) of Sb2S3 solar cells is raised from 6.25% (control device) to 7.12%. This research demonstrates that interface passivation is an effective means of enhancing the PCE of Sb2S3 solar cells.

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.

Band offset engineering in antimony sulfide (Sb2S3) solar cells, using SCAPS simulation: A route toward PCE > 10%

Antimony Sulfide (Sb2S3) is intriguing wide bandgap photovoltaic (PV) material, having great potential for next generation PV devices. The record power conversion efficiency (PCE) for Sb2S3 solar cells is 8.00%, far from its Schockley-Quiser (SQ) limit of 28.64%. Such mediocre performance is mainly attributed to severe interface-induced recombination losses, stemming from mismatched energy-level alignment, and defects at the interfaces. In this work, rational designing, and simulation of Sb2S3 solar cells was performed using solar cell and capacitance (SCAPS). Band offset optimization endorse Zn(O0.3S0.7) and CuSCN as the optimal electron and hole transport layer (ETL and HTL), respectively. The near ideal Zn(O0.3S0.7)/Sb2S3 interface inhibits the detrimental (interface induced) non-radiative losses, leading to substantial improvement in all the device parameters. Simulation results predict spectacular PCE of 13.88% in regular (n−i−p), and 15.89% in HTL-free Sb2S3 solar cells. This work provides genuine recommendations for the fabrication of cost-competitive, eco-friendly, and high PCE-Sb2S3 solar cells.

4.9% Efficient Sb2S3 Solar Cells from Semitransparent Absorbers with Fluorene-Based Thiophene-Terminated Hole Conductors.

Fluorene-based hole transport materials (HTMs) with terminating thiophene units are explored, for the first time, for antimony sulfide (Sb2S3) solar cells. These HTMs possess largely simplified synthesis processes and high yields compared to the conventional expensive hole conductors making them reasonably economical. The thiophene unit-linked HTMs have been successfully demonstrated in ultrasonic spray-deposited Sb2S3 solar cells resulting in efficiencies in the range of 4.7-4.9% with an average visible transmittance (AVT) of 30-33% (400-800 nm) for the cell stack without metal contact, while the cells fabricated using conventional P3HT have yielded an efficiency of 4.7% with an AVT of 26%. The study puts forward cost-effective and transparent HTMs that avoid a post-coating activation at elevated temperatures like P3HT, devoid of parasitic absorption losses in the visible region and are demonstrated to be well aligned for the band edges of Sb2S3 thereby ascertaining their suitability for Sb2S3 solar cells and are potential candidates for semitransparent applications.

Oriented Organization of Poly(3‐Hexylthiophene) for Efficient and Stable Antimony Sulfide Solar Cells

Poly(3‐hexylthiophene) (P3HT), as a traditional organic hole‐transporting material (HTM), is widely used in thin‐film solar cells due to its high charge mobility and good thermal stability. However, the P3HT films obtained by the traditional method are amorphous, which is unfavorable to hole extraction and transport. Here, a low‐toxicity solvent 1,2,4‐trimethylbenzene (TMB) was used as the solvent instead of the commonly used halogen solvent chlorobenzene (CB) to dissolve P3HT. Thus, the self‐assembled nanofibrous P3HT film was prepared and applied as HTM in the newly emerged Sb2S3 solar cells. According to the density functional theory calculations, the interface contact between TMB‐P3HT and Sb2S3 was enhanced via the bonding interaction of S in P3HT and Sb in Sb2S3. Through transient absorption spectroscopy characterization, the enhanced interface contact improves the charge extraction ability of TMB‐P3HT when compared to the CB‐P3HT film. Thus, the TMB‐P3HT‐based Sb2S3 solar cell delivers a power conversion efficiency of 6.21%, which is 9.7% higher than that of the CB‐P3HT‐based device. Furthermore, the dopant‐free TMB‐P3HT‐based Sb2S3 devices exhibit excellent environmental stability compared with Spiro‐OMeTAD‐based devices. This work demonstrates that the application of P3HT and the solvent engineering of HTM are applicable strategies for developing Sb2S3 solar cells with high efficiency and stability.

Low processing temperatures explored in Sb2S3 solar cells by close-spaced sublimation and analysis of bulk and interface related defects

Low processing temperatures explored in Sb2S3 solar cells by close-spaced sublimation and analysis of bulk and interface related defects

A Robust Hydrothermal Sulfuration Strategy toward Effective Defect Passivation Enabling 6.92% Efficiency Sb2S3 Solar Cells

Sulfuration is an efficient route for fabricating metal sulfides photovoltaic devices with high‐quality absorber layer, reduced S vacancy, and high device performance. However, traditional sulfuration processes reported thus far generally suffer from low activity, inert atmosphere, high operating temperature, and ineffective defect passivation, all of which increase manufacturing dangerousness, complicacy, and cost. Simultaneously fulfilling the goals of high reactivity, mild fabrication condition, and efficient defect passivation remain a major challenge for sulfuration, which may be addressed, as demonstrated herein, with the development of a (NH4)2S‐induced hydrothermal sulfuration process in Sb2S3 solar cells. By optimizing the hydrothermal sulfuration process through the use of different amounts of (NH4)2S, an encouraging efficiency of 6.92% has been reached. In addition, the crystallinity of the Sb2S3 film can be obviously improved even under the mild heating conditions (i.e., 160 °C, 120 min). Furthermore, only one hole trap can be identified for the Sb2S3 device after hydrothermal sulfuration, and the trap density is significantly reduced. This innovative sulfuration system introduces a robust approach toward the goal of high‐efficiency metal sulfide solar cells compatible with simple hydrothermal process.

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.

Flexible Substrate‐Structured Sb2S3 Solar Cells with Back Interface Selenization

AbstractAntimony sulfide (Sb2S3) with a 1D molecular structure has strong bending characteristics, showing great application potential in flexible devices. Herein, the flexible substrate‐structured Sb2S3 solar cells is developed and improve device performances by the back interface selenization. The high‐quality Sb2S3 film with an optimal thickness of 1.8 µm, ensuring efficient spectra utilization, is deposited on flexible Mo foils by the rapid thermal evaporation technique. To solve the issues of back interfacial recombination and charge transport, the 20 nm MoSe2 layer between Sb2S3 film and Mo foil is fabricated by substrate selenization in the tube furnace. Further investigations indicate that the MoSe2 layer improves the interfacial energy band alignments and induces the [hk1] orientation of Sb2S3 film, thereby passivating defects and enhancing the carrier transport capacity. The flexible solar cell in the structure of Mo foil/MoSe2/Sb2S3/CdS/ITO/Ag, exhibiting good flexibility to stand thousands of bending, achieves an efficiency of 3.75%, which is the highest for Sb2S3 devices in substrate configuration. The presented flexible structure and back interfacial selenization study will provide new prospects for inorganic Sb2S3 thin film solar cells.

Negative-pressure sulfurization of antimony sulfide thin films for generating a record open-circuit voltage of 805 mV in solar cell applications

Herein, we developed a new sulfurization method to obtain S-rich Sb2S3, which passivated the internal deep-level defects of the film. Finally, a record open-circuit voltage of 805 mV was achieved, which is the highest value for Sb2S3 solar cells.

Interfacial Engineering of High-Performance, Solution-Processed Sb2S3 Phototransistors.

Antimony sulfide, as a binary chalcogenide, has attracted great attention in the field of optoelectronics in recent years, particularly in photovoltaics, because of its striking merits such as earth elements abundance, excellent stability, chemical versatility, and solution processability. With the rapid development of fabrication techniques and device engineering, the device performance of Sb2S3 solar cells has experienced an unprecedented success. However, photodetectors based on Sb2S3 were barely reported, especially based on the transistor configuration. In this work, we prepared high quality Sb2S3 thin films via a sol-gel method, and Sb2S3 thin films were deposited on zinc-tin oxide based field-effect transistors. Furthermore, an additional electron transport layer was inserted between the Sb2S3 layers and the zinc-tin oxide channels and archived high-performance phototransistors with proper interfacial engineering. The optimized devices exhibited extremely high photosensitivity (106), low dark current (∼10 pA) and noise (∼11 fA Hz-1/2), high detectivity (1 × 1013 Jones), and superior device stability, indicating great potential for next generation solution-processed photodetectors.

Efficient In Situ Sulfuration Process in Hydrothermally Deposited Sb2S3 Absorber Layers.

Sulfuration plays a decisive role in enhancing crystal growth and passivate defects in the fabrication of high-efficiency metal-sulfide solar cells. However, the traditional sulfuration process always suffers from high-price professional equipment, tedious processes, low activity of S, or high toxicity of H2S. Here, we develop a desired in situ sulfuration by introducing tartaric acid additive into the hydrothermal deposition process of Sb2S3. Tartaric acid, sodium thiosulfate, and potassium antimony tartaric can form Sb2Sx-contained (x > 3) as-prepared films. Encouragingly, the annealing becomes an inspiring in situ sulfuration process, which can obtain a more compact absorber layer. In addition, the crystallinity and defect property of the Sb2S3 film are also improved significantly. Finally, we achieve a high-performance Sb2S3 solar cell with a power conversion efficiency of 6.31%, which shows an encouraging enhancement of ∼15% compared with the traditional hydrothermal process. This study provides an innovative way to prepare high-efficiency Sb2S3 solar cells and provides a desirable guide to realize the in situ sulfuration process.

A liquid medium annealing strategy for highly [041]/[141]-oriented planar antimony sulfide solar cells with 7.23% efficiency

Antimony sulfide (Sb2S3) is regarded as one of candidate materials for tandem top cells with silicon based solar cells due to its non-toxicity, appropriate bandgap, high absorption coefficient and good stability. However, restricted by the difficulty of carrier transportation caused by unfavorable orientations of Sb2S3, the power conversion efficiency (PCE) is still relatively low. In this work, a new annealing method, called liquid medium annealing (LMA), is developed to versatilely regulate the orientation of Sb2S3 films by controlling the concentration of Se22--OAm. Compared with conventional vapor-assisted annealing, a highly [041]/[141] oriented Sb2S3 film with unique title angles can be skillfully prepared by LMA with top-down model, which facilitates the photo-induced carrier separation along (Sb4S6)n ribbon. Meanwhile, such a LMA tactic can effectively tailor the band alignment at back contact by raises the valence band maximum (VBM) of Sb2S3, and then reducing hole collection barrier. Finally, a high PCE of 7.23% is achieved and considered the first echelon in planar Sb2S3 solar cells.

Sulfur-Vacancy Passivation via Selenium Doping in Sb2S3 Solar Cells: Density Functional Theory Analysis

Antimony sulfide (Sb2S3) has attracted great attention during the past few decades as a light-harvesting material for solar cells owing to its earth abundance and low toxicity. Meanwhile, various point defects limit the efficiency improvement below the power conversion efficiency (PCE) of 10%, especially for S vacancy defects with lower defect formation energy. However, recent experiments have reported that Se doping has suppressed the density of defects and improved photoelectric performance in Sb2S3 solar cells. We adopt the first principles to simulate defect formation energies, charge localization, phonon spectrum, and defect migration dynamics for Sb2S3 structures, indicating that Se doping contributes to increasing the formation energy and inhibiting the formation of the sulfur vacancy defect. Meanwhile, the addition of Se also reduces the overlap between vibrational configurations in initial and final states, suppresses nonradiative electron–hole recombination, prolongs the minority carrier lifetime, and decreases charge and energy losses in Sb2S3 solar cells. The results contribute to the atomistic understanding of the properties of sulfur-vacancy passivation via Se doping and afford the design of high-performance optoelectronic materials.