Process ambient effects on amorphous phase control of Sn-doped CuI films: Towards flexible transparent photodetector application

Herein, process ambient effects on controlling the amorphous phase of Sn-doped CuI films (Sn-CuI) via a direct solution spin coating are reported. The structural analysis reveals that the Sn-CuI films fabricated in the glove box exhibit an amorphous phase, whereas films processed in the atmospheric environment have a crystalline phase. XPS and elemental mapping analysis validate Cu-rich chemical composition for prepared CuI and Sn-CuI films, and morphology and uniformity of the films are manifested by scanning electron microscopy (SEM). The optical transparency (∼60%), the highest photosensitivity (395.25 ± 25.26%), photoresponsivity (R_ph= (214 ± 21.35)mA/W), linear dynamic range (LDR=(15.38 ± 0.67)dB) and others, under 365 nm are achieved for Sn-CuI devices at V_b = 3 V. These results suggest that this platform can be a potential material for flexible transparent photodetectors.