Multilayered Nanometer Thick Films of n-MoS2 QD/n-MoS2/p-CuO as p–n Heterojunctions for Self-Powered Flexible Photodetectors

The present study has investigated the photoresponse of n-MoS2 QDs/n-MoS2/p-CuO, a hybrid dimensional nanoscale heterostructure fabricated on a flexible Ag-coated Kapton substrate. The fabricated flexible heterostructure demonstrates a significant response toward ultraviolet (UV) (376 nm) to near-infrared (NIR) (1064 nm) wavelengths, even in the self-powered mode. The type-II heterostructure formed between the n-MoS2 and p-CuO layers offers the necessary built-in potential for separating and transporting photogenerated electron–hole pairs. The fabricated flexible nanodimensional heterostructure offers responsivities of 28, 54, and 83 μA/W for illuminating radiations in UV, visible, and NIR regions, respectively, in the self-biased mode. The response times [rise time (τr)/fall time (τf)] for the fabricated flexible heterostructure were found to be 81.12 ms/83.47 ms, 77.36 ms/85.73 ms, and 75.62 ms/81.92 ms for the illumination of radiations lying in the UV, visible, and NIR wavelength regions, respectively. The obtained photoresponse demonstrates that the fabricated MoS2 QDs/n-MoS2/p-CuO hybrid dimensional flexible heterostructure will be a potential candidate for the futuristic era of flexible and ultrarapid photodetection applications.