Sb2S3 Thin Films Research Articles

Exfoliated 2D Antimonene‐Based Structures for Light‐Harvesting Photoactive Layer of Highly Stable Solar Cells

From Oxidized 2D Antimonene to Photoactive Sb2S3 In article number 2200038, Joseph G. Shapter, Munkhbayar Batmunkh, and co-workers converted surface-oxidized 2D antimonene sheets to photoactive Sb2S3 light absorber for highly stable solar cells. Highly crystalline Sb2S3 thin films with large grain sizes are obtained by subsequent annealing steps in air and then in a glove box. The devices exhibite outstanding operational stabilities including being able to withstand harsh moisture, light exposure and thermal stress.

Bi Doped Sb2S3 Thin Film Synthesized by a Two-Step Approach with Enhanced Photoelectrochemical Water Splitting Performance

Photoelectrochemical water splitting (PEC) is believed as a promising approach to address the energy and environmental crisis. Here, we adopted a simple two-step method to synthesize bare Sb2S3 film, and then employed a Bi element doping strategy to improve the PEC performance of obtained bare Sb2S3. The obtained Bi-Sb2S3 exhibited an increased photocurrent density, 2.8 mA cm−2 at 1.23 VRHE and a negative shift of onset potential, compared to bare Sb2S3. The enhancement in PEC performance of Bi-Sb2S3 could be attributed to the expanded light absorption range, increased electron carrier concentration and improved charge transfer ability.

Efficient Sb2S3 solar cells employing favorable (Sb4S6)n ribbon orientation via hydrothermal method

Sb2S3 is a promising photoactive material that has attracted extensive research attention, owing to its excellent optical and electrical properties. Sb2S3 has a one-dimensional ribbon structure, and the growth direction of the ribbons significantly changes the carrier transport characteristics of the Sb2S3 thin-film, thereby influencing the performance of Sb2S3 photoelectric devices. In this study, Sb2S3 thin-films are successfully prepared using hydrothermal synthesis. By adjusting the hydrothermal temperature, Sb2S3 thin-films realized the preferred change of orientations: from (hk0) to (hk1). When the hydrothermal temperature is 140 °C, the Sb2S3 thin-film exhibits (221) and (211) preferential growth. The device parameters of Sb2S3 solar cells based on (hk1)-oriented Sb2S3 thin-film are effectively improved compared with those based on (hk0)-oriented Sb2S3 thin-film, and their power conversion efficiency reaches 5.56%. This study may provide guidance for the hydrothermal synthesis of Sb2S3 optoelectronic materials and devices with desirable preferred orientations.

Fabrication of Sb2S3 solar cells by close space sublimation and enhancing the efficiency via co-selenization

As a new-type absorber material, antimony sulfide (Sb2S3) possesses the advantages of earth-abundant elemental contents, low-toxic constituents, appropriate photoelectric properties, and unique one-dimensional crystal structure. We utilized the close space sublimation technique to deposit high-quality Sb2S3 thin-film with (hk1)-preferred orientation by controlling source temperature. Then, Sb2S3 thin film solar cells with the superstrate structure of FTO/CdS/Sb2S3/Au were fabricated, achieving a conversion efficiency of 2.86%. To further enhance efficiency, co-selenization process was employed in the Sb2S3 thin films by co-sublimation, which improve the crystallinity of films, increase grain size and form stronger (hk1)-preferred orientation. In addition, co-selenization process can adjust band gap value and enhance junction quality. By these approaches, we enhanced the short circuit current density (Jsc) of Sb2S3 solar cell efficiently. The Sb2S3 solar cell fabricated by CSS achieved an efficiency of 4.45% using co-selenization process. These methods can be applied to other chalcogenides thin-film solar cells, providing a practical way for the device performance improvement.

Controllable (H K 1) Preferred Orientation of Sb2s3 Thin Films Fabricated by Pulse Electrodeposition

Controllable (H K 1) Preferred Orientation of Sb2s3 Thin Films Fabricated by Pulse Electrodeposition

Depleted Sb2S3 Thin Film Photoconductive Detectors with Fast Response Speed and High Polarization Sensitivity

AbstractAntimony sulfide (Sb2S3) with high absorption coefficient reveals great potential for photodetectors (PDs) in various fields of military and national economy. A new type of depleted Sb2S3 thin film photoconductive detector by using titanium dioxide (TiO2) interlayer with the structure of Au/(glass/TiO2:)Sb2S3/Au is designed. Compared with normal Au/Sb2S3/Au devices, the depleted Sb2S3 PDs obtain a higher switching ratio of 90, greatly enhancing responsivity and specific detectivity. Owing to the electric field of the depletion region, the response time significantly decreases from 23.2 to 0.6 ms. In addition, the anisotropic Sb2S3 film with [120] dominated horizontal orientation is suitable for polarized light detection. The peak‐to‐valley ratio of the depleted Sb2S3 PD reaches 1.3 at polarized light. The results and methods of this study are expected to expand the application of PDs based on Sb2S3 films.

Hydrothermal growth of Sb2S3 thin films on molybdenum for solar cell applications: Effect of post-deposition annealing

The binary chalcogenide material antimony sulfide (Sb2S3) has attracted significant attention as a potential absorber material for photovoltaics (PVs) owing to its suitable bandgap of ~1.7 eV and other unique properties. However, only a few substrate-configured Sb2S3 thin-film solar cells (TFSCs) have been reported, and they demonstrated an extremely low power conversion efficiency (PCE, η < 2.5%) owing to the unfavorable (hk0) orientation of Sb2S3. In most studies, Sb2S3 absorber layers were grown through physical vapor deposition or high-vacuum methods. By contrast, we used a facile hydrothermal approach to deposit Sb2S3 thin films on molybdenum and investigated the effect of post-deposition annealing on the structure, orientation, and morphology of Sb2S3 thin films. Annealing at temperatures ranging from 0° to 350°C transformed the Sb2S3 thin films from nearly amorphous to polycrystalline with large, horizontally aligned plate-like grains. All the annealed Sb2S3 thin films were confirmed to have a preferred orientation along the (hk0) crystal direction. The fabricated substrate-configured TFSCs with SLG/Mo/Sb2S3/CdS/i-ZnO/Al-doped ZnO/Al configuration exhibited the highest PCE of ~1.0%. Further, over 95% of this initial efficiency was maintained after 90 days. We also addressed the underlying reasons for the low efficiency of Sb2S3 TFSCs to provide a pathway for improving the device performance in the future.

Fabrication of Sb2S3 Thin Films by Low-Temperature Plasma-Sulfurizing Metallic Sb Layers

In this work, antimony sulfide (Sb2S3) thin films were prepared by low-temperature plasma (about 190 °C) sulfidation of antimony metal layers, and the sulfidation mechanism was investigated. Solid sulfur powder was used as the sulfur source, and the reaction process did not exhaust toxic gases. The relevant process parameters, including the reaction pressure, radio frequency (RF) power, and sulfurization time, were also optimized. Under conditions of an RF power of 180 W (approximately 190 °C), a curing time of 60 min, and a working pressure of 30 Pa, we prepared a smooth, pinhole-free, (211) preferentially oriented Sb2S3 thin film. The film obtained good photocurrent response and a suitable band gap of 1.74 eV. The properties and structures of the Sb2S3 thin film were characterized by optical emission spectroscopy, high-resolution scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and UV and Raman spectroscopies.

Structural, optical, and morphological characterization of Sb2S3 thin films grown by pulsed laser deposition

Antimony sulfide thin films were deposited on glass substrates at room temperature by pulsed laser deposition using pellets of Sb2S3 as the target. The structural characterization showed that the as-grown films have a high amorphous contribution, and the annealed samples have the Sb2S3 orthorhombic phase. The values for the calculated crystal sizes of 27, 25, and 26 nm for the annealing temperatures of 250, 275, and 300 °C, respectively, for the case of transmission for the as-grown sample amount to 30%, while for the annealed samples, the value is less than 10%. In the reflection measurements, the as-grown sample and the one annealed at 250 °C present lower values at 10%, while for the samples annealed at 275 and 300 °C, the reflection values are between 25% and 35%. On the other hand, the bandgap through the Tauc’s parabolic band method was calculated, with its value for the as-grown sample being 1.92 eV, while for the samples annealed at 250, 275, and 300 °C, the bandgap values are 1.31, 1.66, and 1.29 eV, respectively. The atomic percentage determined by Energy Dispersive Spectroscopy was 36% Sb and 64% S for the as-grown sample, while for the annealed samples, the percentage of sulfur increases, and the percentage of antimony decreases until a final value of 30.5% Sb and 69.5% S for the sample annealed at 300 °C.

Sb2S3 thin films by ultrasonic spray pyrolysis of antimony ethyl xanthate

Synthesis of antimony chalcogenides, especially Sb2S3, by facile and area scalable in-air chemical methods, such as spray pyrolysis, from cost-effective chemicals is certain to accelerate development of the related thin film solar cell technology. In this study, antimony ethyl xanthate, a scarcely studied halogenide-free precursor, is proven to be suitable for the deposition of conformal phase pure crystalline Sb2S3 thin films via ultrasonic spray pyrolysis in air by a two-step process. First, a solution of antimony ethyl xanthate with thiourea in a molar ratio of 1/3, or with thioacetamide in a molar ratio of 1/10 was sprayed onto a glass/ITO/TiO2 substrate by ultrasonic spray pyrolysis at 215°C to yield amorphous phase pure Sb2S3 thin films. Second, performing post-growth heat treatment in vacuum at 225°C, was the key to produce phase pure conformal thin films of crystalline Sb2S3 (Eg 1.8 eV) with S/Sb atomic ratio of 1.46 by using thiourea, and 1.41 by using thioacetamide, respectively. Spraying solutions of antimony ethyl xanthate at ≥135°C resulted in the formation of the Sb2O3 phase. Adding thiourea or thioacetamide to the spray solution prevented the oxidation of the growing Sb2S3 layer during deposition at 135°C, 165°C, and 215°C. The suppressed oxidation of Sb2S3 layers is attributed to the liquid state of thiourea and thioacetamide in these conditions.

Zn(O,S) Buffer Layer for in Situ Hydrothermal Sb2S3 Planar Solar Cells.

Hydrothermal deposition is emerging as a highly potential route for antimony-based solar cells, in which the Sb2(S,Se)3 is typically in situ grown on a common toxic CdS buffer layer. The narrow band gap of CdS causes a considerable absorption in the short-wavelength region and then lowers the current density of the device. Herein, TiO2 is first evaluated as an alternative Cd-free buffer layer for hydrothermally derived Sb2S3 solar cells. But it suffers from a severely inhomogeneous Sb2S3 coverage, which is effectively eliminated by inserting a Zn(O,S) layer. The surface atom of sulfur in Zn(O,S) uniquely provides a chemical bridge to enable the quasi-epitaxial deposition of Sb2S3 thin film, confirming by both morphology and binding energy analysis using DFT. Then the results of the first-principles calculations also show that Zn(O,S)/Sb2S3 has a more stable structure than TiO2/Sb2S3. The resultant perfect Zn(O,S)/Sb2S3 junction, with a suitable band alignment and excellent interface contact, delivers a remarkably enhanced JSC and VOC for Sb2S3 solar cells. The device efficiency with the TiO2/Zn(O,S) buffer layer boosts from 0.54% to 3.70% compared with the counterpart of TiO2, which has a champion efficiency of Cd-free Sb2S3 solar cells with a structure of ITO/TiO2/Zn(O,S)/Sb2S3/Carbon/Ag by in situ hydrothermal deposition. This work provides a guideline for the hydrothermal deposition of antimony-based films upon a nontoxic buffer layer.

The low temperature pyrolysis preparation of In2S3 thin film and its application in Sb2S3 thin film solar cells

In2S3 thin films were successfully prepared by the low temperature pyrolysis of indium-butyldithiocarbamate (In-BDCA) complex at 200 °C for 30 min and first applied as the electron transport layer in Sb2S3 thin film solar cells. The influence of the In-BDCA complex content in the precursor solution on the microstructure of the In2S3 thin films was investigated and the photovoltaic performance of the corresponding Sb2S3 thin film solar cells was evaluated. The result revealed that In2S3 thin film with 2:1 possessed compact and full-coverage surface morphology and its thickness was 25 nm. The corresponding Sb2S3 thin film solar cells achieved the photoelectric conversion efficiency (PCE) of 2.87% with the open-circuit voltage (Voc) of 0.60 V, short-circuit current density (Jsc) of 10.38 mA cm−2, fill factor (FF) of 46.40%. When the preparation temperature of Sb2S3 thin films increased from 200 °C to 300 °C, the corresponding Sb2S3 thin film solar cells achieved the PCE of 4.03% with the Voc of 0.66 V, Jsc of 12.56 mA cm−2, FF of 48.63%. This result demonstrated that the In2S3 thin film can be applied as the efficient electron transport layer in Sb2S3 thin film solar cells.

Defects regulation of Sb2S3 by construction of Sb2S3/In2S3 direct Z-scheme heterojunction with enhanced photoelectrochemical performance

Antimony sulfide (Sb2S3), as a narrow band-gap semiconductor with strong visible light absorption ability, nevertheless due to the existence of a large number of defective energy levels, the application in the field of PEC water splitting was limited. This paper aimed to construct Sb2S3/In2S3 direct Z-scheme heterojunction to effectively eliminate the adverse effect of defective energy level on the photoelectrochemical performance of Sb2S3. Cell-like Sb2S3 thin films were prepared on ITO substrates by simple hydrothermal method, followed by using solvothermal method, the Sb2S3/In2S3 direct Z-scheme heterojunction was successfully constructed. The IPCE values of Sb2S3/In2S3 could reach 10.19 % (735 nm) compared with pure Sb2S3 (4.22 %). Both the separation and injection efficiency could be improved from 3.35 % and 31.69 % to 5.19 % and 61.48 %, respectively. The maximum photocurrent density was 1.24 mA/cm2 at 1.23 V vs. RHE, which was 5.6 times higher than pristine Sb2S3 (0.22 mA/cm2). Moreover, an earlier onset potential was observed (~0.7 V vs. RHE), showing an improvement of 0.3 V when compared to the pristine Sb2S3. This work provided a new idea for the application of antimony chalcogenides in the field of PEC water splitting and the construction of efficient photoelectric devices.

Thermal decomposition of tris(O-ethyldithiocarbonato)-antimony(III)\u2014a single-source precursor for antimony sulfide thin films

Thermal decomposition of tris(O-ethyldithiocarbonato)-antimony(III) (1), a precursor for Sb2S3 thin films synthesized from an acidified aqueous solution of SbCl3 and KS2COCH2CH3, was monitored by simultaneous thermogravimetry, differential thermal analysis and evolved gas analysis via mass spectroscopy (TG/DTA-EGA-MS) measurements in dynamic Ar, and synthetic air atmospheres. 1 was identified by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) measurements, and quantified by NMR and elemental analysis. Solid intermediates and final decomposition products of 1 prepared in both atmospheres were determined by X-ray diffraction (XRD), Raman spectroscopy, and FTIR. 1 is a complex compound, where Sb is coordinated by three ethyldithiocarbonate ligands via the S atoms. The thermal degradation of 1 in Ar consists of three mass loss steps, and four mass loss steps in synthetic air. The total mass losses are 100% at 800 °C in Ar, and 66.8% at 600 °C in synthetic air, where the final product is Sb2O4. 1 melts at 85 °C, and decomposes at 90–170 °C into mainly Sb2S3, as confirmed by Raman, and an impurity phase consisting mostly of CSO22− ligands. The solid-phase mineralizes fully at ≈240 °C, which permits Sb2S3 to crystallize at around 250 °C in both atmospheres. The gaseous species evolved include CS2, C2H5OH, CO, CO2, COS, H2O, SO2, and minor quantities of C2H5SH, (C2H5)2S, (C2H5)2O, and (S2COCH2CH3)2. The thermal decomposition mechanism of 1 is described with chemical reactions based on EGA-MS and solid intermediate decomposition product analysis.

Doping Strategies in Sb2 S3 Thin Films for Solar Cells.

Sb2 S3 is an attractive solar absorber material that has garnered tremendous interest because of its fascinating properties for solar cells including suitable band gap, high absorption coefficient, earth abundance, and excellent stability. Over the past several years, intensive efforts have been made to enhance the photovoltaic efficiencies of Sb2 S3 solar cells using many promising approaches including interfacial engineering, surface passivation, additive engineering, and band-gap engineering of the charge transport layers and active light absorbing Sb2 S3 materials. Recently, doping strategies in Sb2 S3 light absorbers have gained attention as they promise to play important roles in controlling band gap, regulating film morphology, and passivating grain boundaries, and thus resulting in enhanced carrier transport, which is one of the most challenging issues in this cutting-edge research field. In this review, after a brief introduction to Sb2 S3 , an overview of Sb2 S3 solar cells and their fundamental properties are provided. Recent advances in doping strategies in Sb2 S3 thin films and solar cells are then discussed to provide in-depth understanding of the effects of various dopants on the photovoltaic properties of Sb2 S3 materials. In conclusion, the personal perspectives and outlook to the future development of Sb2 S3 solar cells are provided.

Synthesis and characterization of Bi-doped antimony sulphide thin films for solar absorption applications

Producing stable semiconducting thin films with low band gap energy by a viable technique is challenging for solar energy harvesting. Herein, Bi-doped Sb2S3 thin films have been deposited on glass substrates by chemical bath deposition (CBD) technique followed by annealing at 400 °C. X-ray diffraction (XRD) patterns confirmed the orthorhombic phase of Sb2S3 and successful incorporation of Bi+3 in the host lattice. Raman spectroscopy revealed the characteristic vibrational modes of Sb2S3. Surface of films became smoother and compact with increasing Bi contents. Samples showed wide absorption range in the visible region. Band gap energy (Eg) values were estimated using Tauc's relation and a blue shift in the absorption edge was observed with addition of Bi, thus Eg increased from 1.58 to 1.71 eV. Higher values of absorption coefficient and absorption edge in the visible region suggest that the prepared Sb2S3 thin films can be a right choice of an absorber layer.

Fabrication of [hk1]-oriented Sb2S3 thin films from Sb-S molecular precursor ink based on alcohol solvent

In this work, we deposited Sb2S3 thin film with a benign molecular precursor ink based on alcohol solvent. Sb2S3 thin films with dense morphology, good crystallinity, and smooth surface were successfully prepared by optimizing the S/Sb ratio in the precursor. As-synthesized films have [hk1] preferred orientation, which is beneficial for the charge transport. The optical band gap of Sb2S3 thin film is inversely proportional to the S/Sb ratio in the precursor. This work provides a new idea and method for the application of Sb2S3 in photovoltaic.

A facile two-step preparation of compact and crystalline Sb2S3 thin film for efficient solar cells

The two-step preparation of compact and crystalline Sb2S3 thin films was firstly reported using the pyrolysis of the Sb-butyldithiocarbamate complex solution in DMF. The porous and amorphous Sb2S3 thin films were successfully prepared at 170 °C for 30 min, and then can be converted to compact and crystalline Sb2S3 thin films at 200 °C for 30 min or 300 °C for 2 min. The corresponding solar cells with the architecture of FTO/TiO2 compact layer/Sb2S3/spiro-OMeTAD/Au achieved the photoelectric conversion efficiency of 4.16% at 200 °C and 5.05% at 300 °C. The two-step preparation of the compact and crystalline Sb2S3 thin films can provide the feasible approach for the fabrication of various microstructure thin film solar cells and the low preparation temperature of 200 °C was also attractive to assemble the flexible Sb2S3 thin film solar cells.

AgSbS2-xSex thin films: Structure, composition, morphology and photodetection properties

Photodetectors using silver antimony seleno-sulfide (AgSbS2-xSex) thin films were fabricated and their photo sensing properties in the visible range were evaluated. The thin films were synthesized by combining chemical bath deposition and thermal evaporation techniques. The Sb2S3 thin films were deposited using chemical bath deposition followed by thermal evaporation of silver, varying the thickness from 10 to 80 nm proceeded by selenization via dipping in Na2SeSO3. The thin films were fabricated as glass/Sb2S3/Ag/Se layers with different silver thickness heated at 350 °C for 30 min. X-ray diffraction results showed the cubic structure of AgSbS2-xSex films. Elemental analysis, chemical composition and morphological studies were done using various techniques. The optical absorption in the UV–vis-NIR region spectra of the films with varying Ag content illustrated a wide spectral range for photodetector studies. The bandgap values calculated using Tauc plot method indicated within 1.53–1.75 eV, suitable for photodetector application. The current-voltage studies in the dark and illumination revealed that all the samples were photosensitive in the visible region. Methodical analysis of photoresponse was done using LEDs of various wavelengths at bias voltage of 0.5 and 1 V. All the samples showed a stable and good cyclic photoresponse behavior in the wavelength region between 395–740 nm. Further, the extensive photodetector application of the material was demonstrated by measuring the photoresponse using UV–vis LEDs and different laser power densities. The sensitivity and responsivity factors were calculated. With increase in Ag content, the conductivity of the films was increased and so the photocurrent response. This work asserts the application of AgSbS2-xSex thin films as a photodetector which has been explored till date for its photovoltaic properties only.

Fabrication of metal chalcogenide thin films by a facile thermolysis process under air ambient using metal-3-mercaptopropionic acid complex

We report a facile and low-cost solution-based approach to synthesize various binary, ternary and quaternary metal chalcogenide thin films. Homogeneous metal chalcogenides single precursor is prepared by dissolving metal salt (metal chloride/acetate) in ethanolic/methanolic solution of 3-Mercaptopropionic acid (MPA) at room temperature. High-quality CdS, ZnS, Sb2S3, CuInS2 (CIS) and Cu2ZnSnS4 (CZTS) metal sulfide thin films are successfully synthesized by thermalizing these metal-MPA precursor solution at 350 °C in air for 15 min. The mechanism of metal sulfide formation is analyzed by FTIR and thermogravimetry coupled with mass spectrometry. This study highlights the formation of intermediate metal-MPA complex as a single precursor, which eventually decomposes into metal sulfide upon heating at 350 °C. The film thickness, morphology and composition of metal sulfide can be controlled by the concentration of reactants, deposition cycles and the choice of solvent. XRD, Raman, UV–vis spectroscopy, diffuse reflectance spectroscopy and energy dispersive analyses ascertain the phase purity of the films. Bandgap estimates, morphology, narrow Urbach width with low defect densities in the bandgap region, uniform thickness discerned from cross-section SEM, uniformity in the elemental maps and the photoconductivity studies further confirm high-quality of the films. Attaining molecular-level homogeneous precursor solution and inertness to the air ambient enables precise control on the stoichiometry and the enhanced uniformity of deposited films. This facile method will have potential application in large scale synthesis of different metal chalcogenide thin films by a thermolysis process and is highly suitable for controlling stoichiometry and spatial uniformity of deposited films sought in solar cell, optoelectronic and catalysis applications.