Aqueous‐Solution‐Based Approach Towards Carbon‐Free Sb₂S₃ Films for High Efficiency Solar Cells

Abstract

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. After simple annealing at a temperature as low as 270 °C, the spin-coated precursor solution can generate compact, flat, uniform, and well-crystallized Sb S film. Mechanistic study showed that the formation of Sb-complex with ammonium carboxylates leads to the successful dissolution of Sb O powder. A suitable annealing process was able to generate carbon-free Sb S films. Planar heterojunction solar cell based on the as-prepared Sb S film delivered a power conversion efficiency of 5.57 %, which is the highest efficiency of solution-processed planar heterojunction Sb S solar cells and a high value in all kinds of Sb S solar cells. This research provides a convenient approach for the fabrication of device-quality Sb S films, and highlights solution processing of carbon-free metal chalcogenide thin films as a suitable process for application in optoelectronic devices.

Adjusting Interfacial Chemistry and Electronic Properties of Photovoltaics Based on a Highly Pure Sb2S3 Absorber by Atomic Layer Deposition

“…Dewetting of Sb 2 S 3 on TiO 2 has been frequently reported in the literature, with varying degrees of gravity. 20,22,28,32,39−41 In the case of our ALD-deposited highly pure Sb 2 S 3 , dewetting upon thermal annealing results in a complete deterioration of the conformal coating. Figure 1 compares the results of Sb 2 S 3 layer annealing on TiO 2 -coated fluorine-doped tin oxide (FTO) substrates as observed by scanning electron microscopy (SEM).…”

“…11,38 Another effect is a dewetting that occurs upon annealing and crystallization. 20,22,28,32,39−41 This dewetting hints at a poor chemical compatibility between the oxide of a hard, oxophilic metal ion and the sulfide of a heavier, more polarizable ion. This mismatch may also be related to the presence of deleterious trap states at even morphologically perfect TiO 2 /Sb 2 S 3 interfaces.…”

Enhanced Electrical Conductivity of Sb2S3 Thin Film via C60 Modification and Improvement in Solar Cell Efficiency

“…The Nyquist plots are shown in Figure , and the inset is the equivalent electrical circuit model for the Sb 2 S 3 ‐based thin film solar cell. The equivalent circuit diagram consisted of a series connection of a resistor (R 1 ), a parallel combination of a constant phase element (CPE1), and a resistor (R 2 ) . In this experiment, the resistor R 1 was related to the internal series resistance of the device, and R 1 was the starting point of the real part in the Nyquist plots.…”

Sb2S3 Thickness-Related Photocurrent and Optoelectronic Processes in TiO2/Sb2S3/P3HT Planar Hybrid Solar Cells

“…A thin layer of compact TiO 2 (0.15 M titanium diisopropoxide in ethanol) was spin coated at 4500 rpm for 60 s, followed by annealing at 125 °C for 5 min and 450 °C for 30 min. Deposition of Sb 2 S 3 on the top of the TiO 2 thin layer was performed by a chemical bath deposition (CBD) method [5, 10, 22]. An acetone solution containing SbCl 3 (0.3 M) was added dropwise into Na 2 S 2 O 3 (0.28 M) with stirring in an ice bath (~ 5 °C).…”

“…Sb 2 S 3 has been increasingly utilized for solid thin-film solar cells because of its moderate bandgap of 1.7 eV and an absorption coefficient of 1.8 × 10 5 cm −1 [1, 2]. Sb 2 S 3 thin films can be prepared by various methods, including spray pyrolysis [3], electrodeposition [4], chemically deposition [5], and thermal vacuum evaporation technique [6]. In Sb 2 S 3 -based photovoltaic device, photoelectric conversion efficiency (PCE) has reached to 5.7–7.5% by improved technology and device design [1, 2, 7–10].…”