Molten Salts Assisted Interfacial Engineering for Efficient and Low‐Cost Full‐Inorganic Antimony Sulfide Solar Cells

Abstract

Antimony sulfide (Sb 2 S 3 ) is emerging as a promising light harvesting material owing to its brilliant photoelectric property. However, the performance of Sb 2 S 3 -based solar cells is partly limited by serious back contact interface recombination and hole transportation resistance. High-efficiency Sb 2 S 3 devices typically use Spiro-OMeTAD and/or Au as back contact materials, but their stability and cost are a concern. In this sense, a surface modification scheme by lithium-doping is first introduced for Sb 2 S 3 via a facile molten salt method. The ions in the molten state have high mobility and activity, enabling doping reactions to complete within a short time. The lithium-doped Sb 2 S 3 thin film has a smooth and well-bonded surface, preferred (hk1) orientations, and an upshifted valence band maximum (VBM), which favors the hole extraction. Finally, a device using carbon as an electrode, which is more than a dozen times cheaper than gold, raises the short-circuit current density (J SC ) from 12.35 to 14.40 mA cm −2 , and the power conversion efficiency (PCE) from 4.47% to 6.16%. This is among the highest PCE reported for full-inorganic Sb 2 S 3 solar cells, which demonstrates a facile interface modification technique via molten alkali salt to improve the performance of Sb 2 S 3 solar cells.

Charge-Carrier Dynamics of Solution-Processed Antimony- and Bismuth-Based Chalcogenide Thin Films

“…Antimony- and bismuth-based chalcogenide semiconductors have attracted tremendous attention in the field of optoelectronics, benefiting from the facile and low-cost processing, superior stability, and ultrahigh and tunable absorption coefficients. In recent years, they have demonstrated great potential for multiple applications, ranging from next-generation thin-film photovoltaics, − photodetectors, , and phototransistors, , to photocatalysis. , In particular, solution-processed Sb 2 S 3 and AgBiS 2 -based solar cells have progressed rapidly. For example, Tang et al proposed a vacuum-assisted solution process for highly efficient Sb 2 S 3 solar cells and achieved a power conversion efficiency (PCE) of 6.78% .…”

Solvent‐Assisted Hydrothermal Deposition Approach for Highly‐Efficient Sb2(S,Se)3 Thin‐Film Solar Cells

“…As is well known, solvothermal processes are more versatile than hydrothermal processes and can be used to create materials that are easily and frequently oxidized in water. There is evidence from numerous studies [21,22] that oxide impurities are present in (Sb 2 (S x Se 1−x ) 3 , 0 < x <1) films made by hydrothermal deposition. However, the oxide impurities might cause more defects that act as recombination centers of electron-hole pairs; and thus, have an impact on carrier transport and lifetime, [23] which is one of the most difficult areas for PCE improvement to address.…”

Flexible Substrate‐Structured Sb2S3 Solar Cells with Back Interface Selenization

“…[2,3] After years of research, Sb 2 S 3 thin film solar cells have achieved great progress in the aspects of structure design, process optimization, defect passivation, and device solar cells is relatively low, which probably results from the energy level mismatch, defect recombination, back contact barrier, and charge transport. [29,30] According to the study of substrate-structured CZTSSe solar cells on Mo substrate, the quality of back interface plays a crucial role in V OC loss, which can be improved by interfacial intercalation such as MoSe 2 , [31] WO 3 , [32] and MoO 3 [33] interlayer. In light of the motivation, it is anticipated that the MoSe 2 layer produced by the reaction of Mo foil and Se sources will regulate the energy bands and passivate interfacial defects in substrate-structured Sb 2 S 3 solar cells.…”