Antimony Selenide Thin Films Research Articles

Morphological and structural properties of antimony selenide thin films deposited with external electric field assistance

A method for producing a thin semiconductor film of antimony selenide (Sb2Se3) via vacuum thermal evaporation with the assistance of an electric field was presented. The morphological, elemental and structural properties of the thin films were characterized using X-ray diffraction and scanning electron microscopy (with energy dispersive X-ray spectroscopy). It was found that an applied constant electric field plays an important role in obtaining Sb2Se3 thin films with the desired morphological and structural properties. The latter is a useful tool for controlling charge transport properties in thin films.

Optimizing Crystal Orientation and Defect Mitigation in Antimony Selenide Thin-Film Solar Cells through Buffer Layer Energy Band Adjustment.

Antimony selenide (Sb2Se3) has sparked significant interest in high-efficiency photovoltaic applications due to its advantageous material and optoelectronic properties. In recent years, there has been considerable development in this area. Nonetheless, defects and suboptimal [hk0] crystal orientation expressively limit further device efficiency enhancement. This study used Zinc (Zn) to adjust the interfacial energy band and strengthen carrier transport. For the first time, it is discovered that the diffusion of Zn in the cadmium sulfide (CdS) buffer layer can affect the crystalline orientation of the Sb2Se3 thin films in the superstrate structure. The effect of Zn diffusion on the morphology of Sb2Se3 thin films with CdxZn1-xS buffer layer has been investigated in detail. Additionally, Zn doping promotes forming Sb2Se3 thin films with the desired [hk1] orientation, resulting in denser and larger grain sizes which will eventually regulate the defect density. Finally, based on the energy band structure and high-quality Sb2Se3 thin films, this study achieves a champion power conversion efficiency (PCE) of 8.76%, with a VOC of 458mV, a JSC of 28.13mA cm-2, and an FF of 67.85%. Overall, this study explores the growth mechanism of Sb2Se3 thin films, which can lead to further improvements in the efficiency of Sb2Se3 solar cells.

Crystalline Antimony Selenide Thin Films for Optoelectronics through Photonic Curing.

Thermal annealing is the most common postdeposition technique used to crystallize antimony selenide (Sb2Se3) thin films. However, due to slow processing speeds and a high energy cost, it is incompatible with the upscaling and commercialization of Sb2Se3 for future photovoltaics. Herein, for the first time, a fast-annealing technique that uses millisecond light pulses to deliver energy to the sample is adapted to cure thermally evaporated Sb2Se3 films. This study demonstrates how photonic curing (PC) conditions affect the outcome of Sb2Se3 phase conversion from amorphous to crystalline by evaluating the films' crystalline, morphological, and optical properties. We show that Sb2Se3 is readily converted under a variety of different conditions, but the zone where suitable films for optoelectronic applications are obtained is a small region of the parameter space. Sb2Se3 annealing with short pulses (<3 ms) shows significant damage to the sample, while using longer pulses (>5 ms) and a 4-5 J cm-2 radiant energy produces (211)- and (221)-oriented crystalline Sb2Se3 with minimal to no damage to the sample. A proof-of-concept photonically cured Sb2Se3 photovoltaic device is demonstrated. PC is a promising annealing method for large-area, high-throughput annealing of Sb2Se3 with various potential applications in Sb2Se3 photovoltaics.

Photoresponse in sequentially stacked antimony selenide thin films

Antimony selenide (Sb2Se3), a binary semiconducting compound has widespread research attention due to its excellent optoelectronic properties in the visible region and usefulness in applications such as solar cells, photosensors and photoelectrodes. The presented study explores the thickness dependent photoresponse in Sb2Se3 thin films, prepared by reactive selenization of antimony films having thickness values of ∼938 nm and ∼1879 nm when stacked second time. Growth orientation along [001] direction was achieved through carefully optimized selenization conditions to enable favourable charge transport in anisotropic Sb2Se3. Predominant Sb2Se3 formation was inferred from x-ray diffraction, Raman spectroscopy, secondary electron microscopy and energy-dispersive X-ray analyses. High optical absorption coefficient values of about 1 × 105 cm−1 and 5.7 × 104 cm−1 were observed for ∼938 nm and ∼1879 nm thick Sb2Se3 thin films. Further, the optoelectronic properties were elucidated through current–voltage and transient photoresponse measurements under dark and illumination conditions. The measurements were done under zero and different bias voltages. Sb2Se3 films having∼ 938 nm thickness exhibited self-driven photoresponse with a responsivity of 4.3×10−8 A W−1 and detectivity of 3.5 × 106 jones respectively, under AM 1.5 G illumination conditions.

Exploring the Feasibility and Performance of Perovskite/Antimony Selenide Four-Terminal Tandem Solar Cells

The tandem solar cell presents a potential solution to surpass the Shockley–Queisser limit observed in single-junction solar cells. However, creating a tandem device that is both cost-effective and highly efficient poses a significant challenge. In this study, we present proof of concept for a four-terminal (4T) tandem solar cell utilizing a wide bandgap (1.6–1.8 eV) perovskite top cell and a narrow bandgap (1.2 eV) antimony selenide (Sb2Se3) bottom cell. Using a one-dimensional (1D) solar cell capacitance simulator (SCAPS), our calculations indicate the feasibility of this architecture, projecting a simulated device performance of 23% for the perovskite/Sb2Se3 4T tandem device. To validate this, we fabricated two wide bandgap semitransparent perovskite cells with bandgaps of 1.6 eV and 1.77 eV, respectively. These were then mechanically stacked with a narrow bandgap antimony selenide (1.2 eV) to create a tandem structure, resulting in experimental efficiencies exceeding 15%. The obtained results demonstrate promising device performance, showcasing the potential of combining perovskite top cells with the emerging, earth-abundant antimony selenide thin film solar technology to enhance overall device efficiency.

Preparation of antimony selenide thin films by electrochemical deposition and application in optoelectronic devices

Antimony selenide (Sb2Se3) has become a potential semiconductor material for a wide range of optoelectronic applications because of its unique one-dimensional crystal structure and corresponding excellent anisotropic optical and electronic properties. Herein, uniform and flat Sb2Se3 thin films with [hk1]-optimized growth orientation are prepared by adjusting the deposition potentials and selenization temperatures using a facile electrochemical deposition method. Then these films are applied in heterojunction-type photodetectors with the structure of Mo/Sb2Se3/CdS/ZnO/ITO/Ag. The best performances are obtained for devices with a deposition potential of −0.55 V and a selenization temperature of 300 °C. At 0 bias, the detector yielded a responsivity of 25.4 mA/W and a detectivity of 1.06 × 1011 Jones at 635 nm visible light with a light intensity of 5 mW. The results show that high-quality Sb2Se3 thin films can be prepared by electrochemical deposition under proper preparation conditions, which lays the foundation for the application of the electrochemical deposition method in the field of optoelectronic devices.

Antimony selenide thin films prepared by thermal evaporation of antimony and selenium elemental sources

Antimony selenide thin films of 140–190 nm in thickness, with different compositions, were prepared at room temperature by using the dual-thermal evaporation technique. The compositional, structural, morphological and optical studies were performed in the as-deposited state and after annealing at 250°C for an hour, using many analytical techniques. The carrier-type, resistivity, carrier concentration and mobility of the annealed films were determined. The obtained thin films, regardless of their composition, exhibited a smooth surface with a high absorption coefficient of greater than 105 cm−1. The optical band gap of the near-stoichiometric film was 1.56 eV, which decreased to 1.32 eV after annealing. However, higher values were determined with increasing Se elements in the films, but these values did not exceed 1.77 eV. This study shows that antimony selenide thin films can be obtained at room temperature using a thermal evaporation technique, and the properties of the films can be improved with annealing.

Photovoltaic performance of magnetron sputtered antimony selenide thin film solar cells buffered by cadmium sulfide and cadmium sulfide /zinc sulfide

Antimony selenide (Sb2Se3)-based thin-film solar cells have recently attracted worldwide attention as an abundant, low-cost, and efficient photovoltaic technology. The highest efficiencies recorded for Sb2Se3 solar cells have been obtained using cadmium sulfide (CdS) as a buffer layer. The Cd-included hybrid buffer layers could be one option to increase device efficiency through more effective usage of light. Therefore, in this work, the effect of single CdS and hybrid CdS/zinc sulfide (ZnS) buffer layers on the photovoltaic performance of Sb2Se3 thin-film solar cells has been investigated in detail. Sb2Se3 thin films have been deposited on molybdenum (Mo)-coated soda-lime glass (SLG) substrates by radio frequency magnetron sputtering technique followed by a post-heat treatment process. The morphological, and structural properties of Sb2Se3 thin films have been investigated by X-Ray Diffraction and Scanning Electron Microscopy. To compare the device performances of single CdS and hybrid CdS/ZnS buffered Sb2Se3 thin-film solar cells, SLG/Mo/Sb2Se3/CdS/ZnS/indium tin oxide (ITO) and SLG/Mo/Sb2Se3/CdS/ITO structures have been fabricated. The findings of this study have revealed a reduction in solar cells’ performance from η=3.93% for CdS buffer to η=0.13% for CdS/ZnS hybrid buffer. The change in the solar cell performance using the CdS/ZnS hybrid buffer has been discussed in detail.

Heterostructured CdS Buffer Layer for Sb2Se3 Thin Film Solar Cell

The antimony selenide thin film solar cells technology becomes promising due to its excellent anisotropic charge transport and brilliant light absorption capability. Especially, the device performance heavily relies on the vertically oriented Sb2Se3 grain to promote photoexcited carrier transport. However, crystalline orientation control has been a major issue in Sb2Se3 thin film solar cells. Herein, a new strategy has been developed to tailor the crystal growth of Sb2Se3 ribbons perpendicular to the substrate by using the structural heterostructured CdS buffer layer. The heterostructured CdS buffer layer is formed by a dual layer of CdS nanorods and nanoparticles. The hexagonal CdS nanorods passivated by a thin cubic CdS nanoparticle layer can promote [211] and [221] directional growth of Sb2Se3 ribbons using a close space sublimation approach. The improved buffer/absorber interface, reduced interface defects, and recombination loss contribute to the improved device efficiency of 7.16%. This new structural heterostructured CdS buffer layer can regulate Sb2Se3 nanoribbons crystal growth and pave the way to further improve the low‐dimensional chalcogenide thin film solar cell efficiency.

Defect engineering in antimony selenide thin film solar cells

The complicated and unconventional defect chemistry of Sb2Se3 largely dictates photovoltaic device performance. This comprehensive review aims to increase understanding of defect engineering, which is essential for further efficiency improvements.

Routes to increase performance for antimony selenide solar cells using inorganic hole transport layers

Simple compound antimony selenide (Sb2Se3) is a promising emergent light absorber for photovoltaic applications benefiting from its outstanding photoelectric properties. Antimony selenide thin film solar cells however, are limited by low open circuit voltage due to carrier recombination at the metallic back contact interface. In this work, solar cell capacitance simulator (SCAPS) is used to interpret the effect of hole transport layers (HTL), i.e., transition metal oxides NiO and MoO x thin films on Sb2Se3 device characteristics. This reveals the critical role of NiO and MoO x in altering the energy band alignment and increasing device performance by the introduction of a high energy barrier to electrons at the rear absorber/metal interface. Close-space sublimation (CSS) and thermal evaporation (TE) techniques are applied to deposit Sb2Se3 layers in both substrate and superstrate thin film solar cells with NiO and MoO x HTLs incorporated into the device structure. The effect of the HTLs on Sb2Se3 crystallinity and solar cell performance is comprehensively studied. In superstrate device configuration, CSS-based Sb2Se3 solar cells with NiO HTL showed average improvements in open circuit voltage, short circuit current density and power conversion efficiency of 12%, 41%, and 42%, respectively, over the standard devices. Similarly, using a NiO HTL in TE-based Sb2Se3 devices improved open circuit voltage, short circuit current density and power conversion efficiency by 39%, 68%, and 92%, respectively.

Antimony Selenide Thin Films by Electrodeposition: Influence of Deposition Conditions and Post‐Deposition Thermal Treatment on Physical and Photoelectrochemical Properties

Herein, Sb2Se3 thin films are obtained by the electrodeposition technique from a single bath on fluorine‐doped tin oxide (FTO) substrates. The electrodeposition conditions such as precursor concentration and applied potential, as well as the annealing temperature, and its influence on the structural, morphological, optical, and photoelectrochemical properties are analyzed. From the cyclic voltammetry measurements, the range of deposition potential is established and from the sweep rate variation, an irreversible and diffusion‐controlled process is assumed. With the chronoamperometric curves, an instantaneous nucleation is concluded. The Se/Sb ratio variation of the precursor solutions demonstrate that the 0.7 ratio is optimal to obtain Sb2Se3 stoichiometric thin films. The conductivity decreases with the increase of the deposition potential, while the highest photosensitivity is obtained with the film deposited at −0.75 V versus the saturated calomel electrode. Regarding the annealing temperature, a compact homogeneous film is obtained in the range from 325 to 425 °C. Therefore, the suitable properties of Sb2Se3 films obtained by electrodeposition and the establishment of optimized deposition conditions for its use in photoelectrochemical cells (PECs) are demonstrated.

Templated Growth and Passivation of Vertically Oriented Antimony Selenide Thin Films for High‐Efficiency Solar Cells in Substrate Configuration

AbstractAntimony selenide (Sb2Se3) is a promising low‐cost photovoltaic material with a 1D crystal structure. The grain orientation and defect passivation play a critical role in determining the performance of polycrystalline Sb2Se3 thin‐film solar cells. Here, a seed layer is introduced on a molybdenum (Mo) substrate to template the growth of a vertically oriented, columnar Sb2Se3 absorber layer by closed space sublimation. By controlling the grain orientation and compactness of the Sb2Se3 seeds, obtain high‐quality Sb2Se3 absorber layers with passive Sb2Se3/Mo interfaces is obtained, which in turn improve the transport of photoexcited charge carriers through the absorber layer and its interfaces. Post‐deposition annealing of absorber layers in ambient air is further utilized to passivate the defects in Sb2Se3 and enhance the quality of the front heterojunction. As a result of systematic processing optimization, Sb2Se3 planar heterojunction solar cells are fabricated in substrate configuration with a champion power conversion efficiency of 8.5%.

Tandem photoelectrochemical and photoredox catalysis for efficient and selective aryl halides functionalization by solar energy

Tandem photoelectrochemical and photoredox catalysis for efficient and selective aryl halides functionalization by solar energy

Enhanced performance of antimony selenide thin film solar cell using PbI2 as a dopant

Antimony selenide (Sb2Se3) is an emerging photovoltaic material. We demonstrate that PbI2 is an effective p-type dopant for Sb2Se3. The Sb2Se3 film was doped by PbI2 by thermal diffusion. Both the hole concentration and conductivity are dramatically increased by doping. We fabricated the Sb2Se3 solar cell using C60 as an electron transport layer by vacuum thermal evaporation. By PbI2 doping, the open-circuit voltage (Voc) is increased from 0.32 to 0.38 V, and the power conversion efficiency is improved from 2.87% to 4.43%. This work provides an effective p-type dopant for Sb2Se3.

Antimony Selenide Thin Film Solar Cells with an Electron Transport Layer of Alq3*Supported by the High Level Talents Project of Hainan Basic and Applied Research Program (Natural Science) (Grant No. 2019RC118), and the Open Fund of the State Key Laboratory of Molecular Reaction Dynamics in DICP (Grant No. SKLMRDK202005).

We fabricated Sb2Se3 thin film solar cells using tris(8-hydroxy-quinolinato) aluminum (Alq3) as an electron transport layer by vacuum thermal evaporation. Another small organic molecule of N,N’-bis(naphthalen-1-yl)-N,N’-bis(phenyl)benzidine (NPB) was used as a hole transport layer. We took ITO/NPB/Sb2Se3/Alq3/Al as the device architecture. An open circuit voltage (Voc) of 0.37 V, a short circuit current density (Jsc) of 21.2 mA/cm2, and a power conversion efficiency (PCE) of 3.79% were obtained on an optimized device. A maximum external quantum efficiency of 73% was achieved at 600 nm. The Jsc, Voc, and PCE were dramatically enhanced after introducing an electron transport layer of Alq3. The results suggest that the interface state density at Sb2Se3/Al interface is decreased by inserting an Alq3 layer, and the charge recombination loss in the device is suppressed. This work provides a new electron transport material for Sb2Se3 thin film solar cells.

Effect of selenisation on the properties of antimony selenide thin films

Antimony Selenide (Sb2Se3) is an important photoconductive semiconductor and it has a band gap of 1.3 eV. It finds applications in solar selective and decorative coating, optical devices and thermoelectric cooling devices. In the present work, Sb2Se3 thin film is prepared by Chemical Bath Deposition (CBD) technique. This method is most suitable for large area samples and it is very simple. Antimony chloride and sodium selenosulfate are used as precursors for the preparation of antimony selenide thin films. It was observed from XPS analysis that antimony oxide was also present as an impurity phase along with antimony selenide. In this work, selenisation is carried out in order to increase the selenium content in the pristine antimony selenide thin films. Selenisation was also done by the method of CBD. These samples were annealed at various temperatures and characterized structurally, morphologically and optically. It was observed that the inclusion of Se has lead to exclusion of oxygen from the surface layers of Antimony Selenide films. Se inclusion has also changed the morphology of Antimony selenide films drastically.

Comparison of antimony selenide thin films obtained by electrochemical deposition and selenization of a metal precursor

In this work, we present a study comparing two methods of Sb2Se3 deposition, namely electrochemical deposition and selenization of a thin-film metallic Sb – precursor deposited by magnetron sputtering. The Sb selenization process was carried out in the range of temperatures from 270 °C to 350 °C in an argon atmosphere enriched with elemental Se vapor. Electrochemical deposition of Sb2Se3 was performed in a three-electrode cell at constant potential. Following electrochemical deposition, the samples were annealed in argon at temperatures ranging from 270 °C to 350 °C. Characterization of the obtained thin films was performed using X-ray diffraction, Raman spectroscopy and optical transmission. Both deposition methods demonstrate successful emergence of the selenide phase, albeit with the presence of varying levels of antimony oxide. The possibility of preferential growth was observed, which is suggested as dependent on growth method and annealing temperature.

Role of thickness and annealing temperature on the structural ordering in vacuum evaporated antimony selenide thin films

ABSTRACTBulk Sb2Se3 is prepared by melt quenching technique and from the differential scanning calorimetry, glass transition (Tg) is greater than ⅔ Tc ≈ ⅔ Tm while Tm>Tc. Sb2Se3 thin films are deposited on the glass substrates by thermal evaporation technique. Effect of thickness and annealing temperature on the structural, morphological and optical properties are studied. An amorphous to crystalline phase transition is observed from X-ray diffraction when the films are annealed at 200 °C. Structural variation, on the increase in annealing temperature causes the width of localized states to increase and hence reductions in band gaps are obtained.

Both Free and Trapped Carriers Contribute to Photocurrent of Sb2Se3 Solar Cells.

Polycrystalline semiconductor films, such as methylammonium lead iodide, cadmium telluride, copper-indium-gallium selenide, etc., are being intensively studied because of their great potential for highly efficient and cost-effective solar cells. Among them, polycrystalline antimony chalcogenide films are also promising for photovoltaic applications because they are nontoxic, stable, and flexible and have a suitable band gap. Considerable effort has already been devoted to improving the power conversion efficiency of antimony chalcogenide solar cells, but their efficiency still lingers below 10% due in part to scarce fundamental optoelectronic studies that help guide their development. Here, we use a combination of time-resolved terahertz and transient absorption spectroscopies to interrogate the optoelectronic behavior of antimony selenide thin films. By combining these two techniques we are able to monitor both free and trapped carrier dynamics and then evaluate their respective diffusion lengths. Our results indicate that trapped carriers remain mobile and can reach charge-collecting interfaces prior to recombination, and therefore, both free and trapped carriers can contribute to the photocurrent of antimony selenide solar cells.