Enhanced efficiency of Cu₂ZnSn(S,Se)₄ solar cells via anti-reflectance properties and surface passivation by atomic layer deposited aluminum oxide

Abstract

Reducing interface recombination losses is one of the major challenges in developing Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells. Here, we propose a CZTSSe solar cell with an atomic layer deposited Al 2 O 3 thin film for surface passivation. The influence of passivation layer thickness on the power conversion efficiency

Defect Control for High‐Efficiency Cu2ZnSn(S,Se)4 Solar Cells by Atomic Layer Deposition of Al2O3 on Precursor Film

“…This suppressed recombination process is one factor leading to V OC enhancement. In summary, in obvious contrast to the interface modification of Al 2 O 3 for kesterite solar cells reported by other researchers, [31][32][33][34] the Al 2 O 3 introduced by the method used in this study can not only optimize the defects but also improve the quality of the absorber bulk.…”

“…It was reported that an Al 2 O 3 layer deposited by ALD on the surface of the absorber layer can reduce the defect density at the CZTSSe/CdS interface [31] or decrease the reflectance from the surface of the absorber. [33] Hao's group at UNSW in Australia think such passivation is from the hydrogen during the deposition of the ALD-Al 2 O 3 layer rather than from Al 2 O 3 . [32,34] Thus, it can be concluded that Al 2 O 3 deposited between the absorber layer and buffer layer can improve the performance because of passivation of the defects, no matter whether it is due to Al 2 O 3 or hydrogen.…”

“…Recently, atomic layer deposition (ALD) has been proven to be an optimal technique due to the intrinsic self-terminating nature of the process. Moreover, aluminum oxide deposited by ALD (ALD-Al 2 O 3 ) can provide a state-of-the-art level of surface passivation on c-Si solar cells, [26] and it also has been widely used in organic, [27] dye-sensitized, [28] perovskite, [29] and chalcogenide thin-film solar cells, [12,[30][31][32][33] thereby improving the device performance. It was reported that an Al 2 O 3 layer deposited by ALD on the surface of the absorber layer can reduce the defect density at DOI: 10.1002/solr.202100181 Cu 2 ZnSn(S,Se) 4 are emerging as promising photovoltaic materials due to their outstanding photoelectrical performances, benign grain boundaries, and Earth-abundant constituent elements.…”

Nanoscale Rear-Interface Passivation in Cu2ZnSn(S,Se)4 Solar Cells through the CuAlO2 Intermediate Layer

“…Additionally, the photoresponse of the fabricated device enhanced in the entire visible region as well as in longer wavelengths (600−1000 nm) with better carrier separation that suggests an improved rear-interface with reduced recombination. 40 The improvement in the CZTSSe absorber quality observed in FESEM images supports the enhancement in the EQE spectra after inserting the CAO nanolayer. Besides, Table S2 summarizes the performance of kesterite TFSCs based on previously reported various passivation layers for the rear interface (Supporting Information).…”

Potential Role of Kesterites in Development of Earth‐Abundant Elements‐Based Next Generation Technology

“…Using a suitable passivation layer can reduce the MoS/Se 2 layer thickness. Various passivation layers have been effectively applied to reduce the thickness of MoS/Se 2 , including Al 2 O 3 , [59,60] MoO 3 , [61] Bi, [62] Ti, [63] CuO, [64] SnO 2 , [65] MoO 2 , [66] carbon, [67,68] graphene oxide, [69] TiN, [70,71] ZnO, [72,73] Ag, [74] TiB 2 , [75] CuAlO 2 , [76] CuGaSe 2 , [77] Al-doped ZnO, [78] Na 2 S, [79,80] etc. [36] The abovementioned back-electrode intermediate layers at the Mo/CZTSSe interface effectively control the Mo(S,Se) 2 layer thickness and offer lower resistance at the back electrode.…”