Correlation between Surface Functionalization and Optoelectronic Properties in Quantum Dot Phototransistors

Quantum dot (QD)-based optoelectronics have attracted significant interest for extensive applications due to their unique photo-functionalities such as excellent optical absorption coefficient, size-dependent bandgap tunability, and facile solution processability. However, the charge transfer correlation between surface functionalization and optoelectronic properties is still not clear. Here, we report highly photosensitive CdSe QDs/solution-processed amorphous oxide semiconductor hybrid phototransistors with highly efficient photo-induced charge carrier transport using molecular metal chalcogenide (MCC) ligands surface functionalization. Furthermore, we comprehensively investigated the photo-induced electron transfer characteristics with respect to various MCC ligands such as Sn, and In2 Se In particular, the interplay among photosensitive chelating MCC ligands of the QDs and trap-free optoelectronic performance of phototransistors was investigated. Compared to -IGZO thin-film transistors and oleic acid-based CdSe QDs/ -IGZO phototransistors, Sn, Sn2 Se and In2 Se -based CdSe QD/ -IGZO phototransistors exhibited ultrahigh photosensitivity of -1, AW-1, and AW-1, respectively, in a broad range of incident light power (0.34 mW cm-2 -11.8 mW cm-2).