Nanoscale physico-chemical investigation of complementary ZnO-Si nanocomposites and their photoconductive behavior

The complementary ZnO-Si nanocomposites were synthesized via facile solution process at room temperature and enhanced photoconductive switching behavior was observed under a white light irradiation. The morphology and atomic/electronic structure of ZnO-Si nanocomposites were investigated by atomic-resolution (scanning) transmission electron microscopy combined with electron energy loss spectroscopy. It is revealed that host ZnO nanorods contained peculiar nm-sized Si-rich phases on the ZnO surface, in which effective band gap was significantly decreased. Our results explain a collaborative interaction between host ZnO nanorods and Si-rich phase which led to an enhancement of photoconductive properties over as-prepared ZnO nanorod.