Grain-Boundary Elimination via Liquid Medium Annealing toward High-Efficiency SbSe Solar Cells.

Suppression of charge recombination caused by unfavorable grain boundaries (GBs) in polycrystalline thin films is essential for improving the optoelectronic performance of semiconductor devices. For emerging antimony selenide (SbSe) materials, the unique quasi-1D structure intensifies the dependence of GB properties on the grain size and orientation, which also increases the impact of defects related to grain structure on device performance. However, these characteristics pose significant challenges in the preparation of thin films.

One-Step Hydrothermal Deposition of AgSbSSe Thin Films for Solar Cell Applications.

AgSbSSe is a promising light-harvesting material for thin film solar cells, characterized by nontoxicity, high chemical stability, and excellent optoelectronic properties. However, the complex chemical composition of AgSbSSe poses significant challenges to thin film preparation, giving rise to an intensive dependence on multi-step preparation methods. Herein, a hydrothermal method is developed for depositing AgSbSSe films and achieves one-step preparation of this kind of thin film materials for the first time.

Temperature-Gradient Solution Deposition Amends Unfavorable Band Structure of Sb(S,Se) Film for Highly Efficient Solar Cells.

Band structure of a semiconducting film critically determines the charge separation and transport efficiency. In antimony selenosulfide (Sb(S,Se)) solar cells, the hydrothermal method has achieved control of band gap width of Sb(S,Se) thin film through tuning the atomic ratio of S/Se, resulting in an efficiency breakthrough towards 10 %. However, the obtained band structure exhibits an unfavorable gradient distribution in terms of carrier transport, which seriously impedes the device efficiency improvement.

Active Passivation of Anion Vacancies in Antimony Selenide Film for Efficient Solar Cells.

Binary antimony selenide (SbSe) is a promising inorganic light-harvesting material with high stability, nontoxicity, and wide light harvesting capability. In this photovoltaic material, it has been recognized that deep energy level defects with large carrier capture cross section, such as V (selenium vacancy), lead to serious open-circuit voltage (V) deficit and in turn limit the achievable power conversion efficiency (PCE) of SbSe solar cells. Understanding the nature of deep-level defects and establishing effective method to eliminate the defects are vital to improving V.

Effect of Energy-driven Molecular Precursor Decomposition on the Crystal Orientation of Antimony Selenide Film and Solar Cell Efficiency.

Antimony selenide (SbSe) consists of 1D (SbSe) ribbons, along which the carriers exhibit high transport efficiency. By adjusting the deposition parameters of vacuum-deposited methods, such as evaporation temperature, chamber pressure, and vapor concentration, it is possible to grow the (SbSe) ribbons vertically or highly inclined towards the substrate, resulting in films with [hk1] orientation. However, the specific mechanisms by which these deposition parameters affect the orientation of thin films require a deeper understanding.

Critical Review on Crystal Orientation Engineering of Antimony Chalcogenide Thin Film for Solar Cell Applications.

The emerging antimony chalcogenide (Sb (S Se ) , 0 ≤ x ≤ 1) semiconductors are featured as quasi-1D structures comprising (Sb S(e) ) ribbons, this structural characteristic generates facet-dependent properties such as directional charge transfer and trap states. In terms of carrier transport, proper control over the crystal nucleation and growth conditions can promote preferentially oriented growth of favorable crystal planes, thus enabling efficient electron transport along (Sb S(e) ) ribbons. Furthermore, an in-depth understanding of the origin and impact of the crystal orientation of Sb (S Se ) films on the performance of corresponding photovoltaic devices is expected to lead to a breakthrough in power conversion efficiency.

KCl Treatment of CdS Electron-Transporting Layer for Improved Performance of Sb(S,Se) Solar Cells.

Antimony sulfoselenide (Sb(S,Se)) is a promising light absorption material because of its high photoabsorption coefficient, appropriate band gap, superior stability, and abundant elemental storage. As an emerging solar material, hydrothermal deposition of Sb(S,Se) solar cells has enabled a 10% efficiency threshold, where cadmium sulfide (CdS) is applied as an electron transport layer (ETL). The high-efficiency Sb(S,Se) solar cells largely employ CdS as the ETL.

Efficient In Situ Sulfuration Process in Hydrothermally Deposited SbS 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 HS. Here, we develop a desired in situ sulfuration by introducing tartaric acid additive into the hydrothermal deposition process of SbS.

Thermally Driven Point Defect Transformation in Antimony Selenosulfide Photovoltaic Materials.

Thermal treatment of inorganic thin films is a general and necessary step to facilitate crystallization and, in particular, to regulate the formation of point defects. Understanding the dependence of the defect formation mechanism on the annealing process is a critical challenge in terms of designing material synthesis approaches for obtaining desired optoelectronic properties. Herein, a mechanistic understanding of the evolution of defects in emerging Sb (S,Se) solar cell films is presented.

Post-Treatment of TiO Film Enables High-Quality SbSe Film Deposition for Solar Cell Applications.

The TiO thin film is considered as a promising wide band gap electron-transporting material. However, due to the strong Ti-O bond, it displays an inert surface characteristic causing difficulty in the adsorption and deposition of metal chalcogenide films such as SbSe. In this study, a simple CdCl post-treatment is conducted to functionalize the TiO thin film, enabling the induction of nucleation sites and growth of high-quality SbSe.

Dopant-free hole-transporting materials for stable Sb(S,Se) solar cells.

Herein, we demonstrate that a thiophene-modified quinoxaline core small molecule can be applied in Sb(S,Se) solar cells. We reveal that the interaction between thiophene and Sb(S,Se) through the Sb-S bond essentially improves the interfacial hole-extraction ability. This study provides a cost-effective dopant-free hole-transporting material for inorganic thin film solar cell applications with excellent stability.

Distinctive Deep-Level Defects in Non-Stoichiometric Sb Se Photovoltaic Materials.

Characterizing defect levels and identifying the compositional elements in semiconducting materials are important research subject for understanding the mechanism of photogenerated carrier recombination and reducing energy loss during solar energy conversion. Here it shows that deep-level defect in antimony triselenide (Sb Se ) is sensitively dependent on the stoichiometry. For the first time it experimentally observes the formation of amphoteric Sb defect in Sb-rich Sb Se .

Direct Hydrothermal Deposition of Antimony Triselenide Films for Efficient Planar Heterojunction Solar Cells.

Antimony selenide (SbSe) has attracted increasing attention in photovoltaic applications due to its unique quasi-one-dimensional crystal structure, suitable optical band gap with a high extinction coefficient, and excellent stability. As a promising light-harvesting material, the available synthetic methods for the fabrication of a high-quality film have been quite limited and seriously impeded both the fundamental study and the efficiency improvement. Here, we developed a facile and low-cost hydrothermal method for in situ deposition of SbSe films for solar cell applications.

Sequential Coevaporation and Deposition of Antimony Selenosulfide Thin Film for Efficient Solar Cells.

Antimony selenosulfide (Sb (S,Se) ) is an emerging low-cost, nontoxic solar material with suitable bandgap and high absorption coefficient. Developing effective methods for fabricating high-quality films would benefit the device efficiency improvement and deepen the fundamental understanding on the optoelectronic properties. Herein, equipment is developed that allows online introduction of precursor vapor during the reaction process, enabling sequential coevaporation of Sb Se and S powders for the deposition of Sb (S,Se) thin films.

Surface Reconstruction of InN Nanosheets for Efficient CO Electroreduction into Formate.

Probing and understanding the intrinsic active sites of electrocatalysts is crucial to unravel the underlying mechanism of CO electroreduction and provide a prospective for the rational design of high-performance electrocatalysts. However, their structure-activity relationships are not straightforward because electrocatalysts might reconstruct under realistic working conditions. Herein, we employ measurements to unveil the intrinsic origin of the InN nanosheets which served as an efficient electrocatalyst for CO reduction with a high faradaic efficiency of 95% for carbonaceous product.

Probing the trap states in N-i-P Sb(S,Se) solar cells by deep-level transient spectroscopy.

In this study, we provide fundamental understanding on defect properties of the Sb(S,Se) absorber film and the impact on transmission of photo-excited carriers in N-i-P architecture solar cells by both deep level transient spectroscopy (DLTS) and optical deep level transient spectroscopy (ODLTS) characterizations. Through conductance-voltage and temperature-dependent current-voltage characterization under a dark condition, we find that the Sb(S,Se) solar cell demonstrates good rectification and high temperature tolerance. The DLTS results indicates that there are two types of deep level hole traps H1 and H2 with active energy of 0.

Composition engineering of SbS film enabling high performance solar cells.

SbS is a kind of stable light absorption materials with suitable band gap, promising for practical applications. Here we demonstrate that the engineering on the composition ratio enables significant improvement in the device performance. We found that the co-evaporation of sulfur or antimony with SbS is able to generate sulfur- or antimony-rich SbS.

Interfacial Engineering by Indium-Doped CdS for High Efficiency Solution Processed Sb(SSe ) Solar Cells.

Sb(SSe ) alloy material is a kind of encouraging material for realistically apposite solar cell because it benefits from high absorption coefficient, suitable bandgap, superior stability, and plentiful elemental storage. Interfacial engineering is vital for effective charge carrier transport in solar cells, which could upgrade the photoelectric conversion efficiency (PCE). Herein, as an interlayer, indium-doped CdS thin film fabricated by chemical bath deposition is found to remarkably enhance the photovoltaic performance of Sb(SSe ) solar cells.

n-Type Doping of SbS Light-Harvesting Films Enabling High-Efficiency Planar Heterojunction Solar Cells.

SbS is a kind of new light-absorbing material possessing high stability in ambient environment, high absorption coefficient in the visible range, and abundant elemental storage. To improve the power conversion efficiency of SbS-based solar cells, here we control the defect in SbS absorber films. It is found that the increase of sulfur vacancy is able to upgrade photovoltaic properties.

Aqueous-Solution-Based Approach Towards Carbon-Free Sb S Films for High Efficiency Solar Cells.

Sb S is a new kind of photovoltaic material that is promising for practical application in solar cells owing to its suitable bandgap, earth-abundant elements, and excellent stability. Here, we report on an aqueous-solution-based approach for the synthesis of Sb S films from easily accessible Sb O as antimony source. In this reaction, 3-mercaptopropionic acid was applied as both solvent and sulfur precursor, aqueous ammonia was employed as a solvent.

VO as Hole Transporting Material for Efficient All Inorganic SbS Solar Cells.

This research demonstrates that VO is able to serve as hole transporting material to substitute organic transporting materials for SbS solar cells, offering all inorganic solar cells. The VO thin film is prepared by thermal decomposition of spin-coated vanadium(V) triisopropoxide oxide solution. Mechanistic investigation shows that heat treatment of VO layer has crucial influence on the power conversion efficiency of device.

A fast chemical approach towards SbS film with a large grain size for high-performance planar heterojunction solar cells.

A facile chemical method is developed for the fabrication of SbS film with a lateral grain size as large as ∼12 μm. A solar cell based on this SbS film achieves a power conversion efficiency of 4.3%, which is the highest value in solution processed planar heterojunction solar cells based on SbS film.

Kesterite Cu2ZnSnS4 as a Low-Cost Inorganic Hole-Transporting Material for High-Efficiency Perovskite Solar Cells.

Kesterite-structured quaternary semiconductor Cu2ZnSnS4 (CZTS) has been commonly used as light absorber in thin film solar cells on the basis of its optimal bandgap of 1.5 eV, high absorption coefficient, and earth-abundant elemental constituents. Herein we applied CZTS nanoparticles as a novel inorganic hole transporting material (HTM) for organo-lead halide perovskite solar cells (PSCs) for the first time, achieving a power conversion efficiency (PCE) of 12.

An ultrasonic study on complex charge ordering phenomena for La(1-x)Sr(x)FeO(3).

The complex charge ordering phenomena for polycrystalline La(1-x)Sr(x)FeO(3) (1/3≤x≤2/3) have been studied by measuring the low temperature magnetization, resistivity and the longitudinal ultrasonic velocity (V(l)). At low doping levels (1/3≤x≤0.5), a dramatic velocity increase is observed below 210 K, and the relative stiffening of V(l) is proportional to the Sr concentration.

Ultrasonic study of the charge mismatch effect in charge-ordered (Nd(0.75)Na(0.25))(x)(Nd(0.5)Ca(0.5))(1-x)MnO(3).

The resistivity, magnetization and ultrasonic properties of charge-ordered polycrystalline (Nd(0.75)Na(0.25))(x)(Nd(0.