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Solution‐processed CuSCN serving as hole transport, electron reflecting layer (HTL, ERL) and Cu dopant source for CdSe/CdTe thin‐film solar has demonstrated high power conversion efficiency (PCE) of ~17%. Two types of solvent, diethyl sulfide (DES) and aqueous ammonia (NH4OH), are explored to deposit CuSCN on CdTe, and both can enhance the performance of CdSe/CdTe solar cells. However, NH4OH solvent is less toxicity, leading to a smoother surface than DES solvent, enabling the deposition of ultra‐thin CuSCN layer and avoiding the high cost of DES. Temperature‐dependent current‐voltage (J‐V‐T) and capacitance‐voltage (C‐V‐T) measurements reveal that the use of CuSCN HTL increases hole concentration in CdTe absorber and significantly reduces back‐contact barrier height. High power conversion efficiency is achievable with the optimal thickness of the CuSCN layer. Our results demonstrate solution‐processed CuSCN HTL for enhancing the efficiency and reducing the cost of CdTe thin‐film solar cells. [ABSTRACT FROM AUTHOR]

The nanoscale electrical and mechanical properties in the CdTe thin films solar cells were investigated using the scanning probe microscopy. The comparative localized electrical and mechanical properties between as-grown and CdCl2 treated CdTe thin films for the grain and grain boundaries were studied using the conductive atomic force microscopy (cAFM) and force modulation microscopy (FMM). An increased electrical behavior and decreased elastic stiffness in the CdCl2 treated thin films were recorded to elucidate the impact from the grain growth of CdTe grains. On applying a simulated working electrical bias into the CdTe thin-film solar cells, the electric field across the CdTe film can increase the softness of CdTe thin film. The results imply the presence of a potential mechanical failure site in the CdTe grain boundary, which may lead to device degradation. [ABSTRACT FROM AUTHOR]

Antimony chalcogenide Sb2Se3 is an emerging photovoltaic absorber due to its appropriate bandgap (≈1.1 eV), high absorption coefficient (>105 cm−1), suitable p‐type conductivity, low toxicity, earth abundance, and excellent stability. However, the stringent growth condition and low photovoltage limit its power conversion efficiency (PCE). Herein, via a combined theoretical and experimental study, interface engineering via an oxygenated cadmium sulfide (CdS) window layer (CdS:O) is found to be an effective approach to improve the device performance of CdS:O/Sb2Se3 solar cells. The sputtered oxygenated CdS:O window layer can be used to replace conventional chemical‐bath‐deposited CdS window layer in the Sb2Se3 devices. The best PCE of 7.01% is demonstrated in the superstrate configuration of fluorine‐doped SnO2/CdS:O/Sb2Se3/graphite with a high open‐circuit voltage of 0.432 V, where Sb2Se3 is fabricated using the close space sublimation technique. The interfacial diffusion between Sb2Se3 and sputtered CdS:O is significantly suppressed by introducing oxygen at the interface, which prevents Cd diffusion and the formation of Cd interstitials. Combined device physics characterizations and theoretical calculations reveal that oxygen in the CdS:O/Sb2Se3 interface can increase depletion region, built‐in voltage, and reduce interfacial recombination. These findings provide the guidance to optimize quasi‐one‐dimensional non‐cubic earth‐abundant chalcogenide photovoltaic devices through interface engineering. [ABSTRACT FROM AUTHOR]