High open‐circuit voltage CuSbS₂ solar cells achieved through the formation of epitaxial growth of CdS/CuSbS₂ hetero‐interface by post‐annealing treatment

Abstract

The earth‐abundant and environmentally‐friendly CuSbS2 solar cells have been struggling with low device performance, especially poor open circuit voltage (Voc). In this work, post‐annealing treatment of the CuSbS2/CdS heterojunction performed on CuSbS2‐based solar cells was firstly reported. With this treatment, we demonstrated CuSbS2 solar cells with a record Voc of 622 mV. The improvement of device performance was found peaked at 250°C post‐annealing which mainly benefits from the significantly boosted open‐circuit voltage and short‐circuit current. The study of microstructure by high‐resolution transmission electron microscopy revealed that such improvement could be attributed to the formation of epitaxial CuSbS2/CdS hetero‐interface upon heat treatment, which reduces the interface defect density that may lead to reduced Voc deficit. Besides, results of photoluminescence and time‐resolved photoluminescence measurements also indicated improved electrical properties of completed devices with higher photoluminescence intensity and longer minority carrier lifetime.

Deep‐Level Defect in Quasi‐Vertically Oriented CuSbS2 Thin Film

“…The X-ray diffraction (XRD) pattern of as-deposited CuSbS 2 thin film on glass is shown in black in Figure 1a Figure S1, Supporting Information). The crystalline orientation of CuSbS 2 on glass is significantly different from our previously fabricated CuSbS 2 grown on Mo-coated glass that shows random orientation as demonstrated in Figure S2, Supporting Information, [10] which is believed to be due to different deposition substrates that exhibit various surface properties. In addition, we have also identified small amount of Sb 2 S 3 secondary phases as marked by asterisk in Figure 1a.…”

Accelerating Electron‐Transfer and Tuning Product Selectivity Through Surficial Vacancy Engineering on CZTS/CdS for Photoelectrochemical CO2 Reduction

“…Heat treatment (HT) is a common strategy for surface and interface engineering in heterojunction structures, which has been widely used to promote grain growth, [ 34 ] improve the crystallinity, [ 35 ] and passivate the interface defects. [ 36 ] Recently, Yan et al. demonstrated that by HT processing of CZTS/CdS, significant efficiency enhancement was achieved in CdS‐buffer based CZTS solar cells.…”

Interface engineering of p-n heterojunction for kesterite photovoltaics: A progress review

“…The certified highest power conversion efficiencies (PCE) of 12.6%, 12.5% and 11.0% have been achieved by using CZTSSe, CZTSe, CZTS absorber, respectively [1][2][3]14]. Note that the PCE of kesterite so far dominates all emerging inorganic thin-film PV technologies, highlighting its potential for cost-effective solar cell applications [15][16][17][18][19][20][21][22]. Nevertheless, the present record PCE of CZTSSe is still lower than the physical limit defined by the Shockley-Queisser (S-Q) theory or first-principles calculations [23][24][25].…”