The Growth and Characterization of ZnO/ZnTe Core–Shell Nanowires and the Electrical Properties of ZnO/ZnTe Core–Shell Nanowire Field Effect Transistor

Abstract

Vertically aligned ZnO/ZnTe core-shell nanowires were grown on a-plane sapphire substrate by using chemical vapor deposition with gold as catalyst for the growth of ZnO core and then followed by growing ZnTe shell using metal-organic chemical vapor deposition (MOCVD). Transmission electron microscope (TEM) and Raman scattering indicate that the core-shell nanostructures have good crystalline quality. Three-dimensional fluorescence images obtained by using laser scanning confocal microscope demonstrate that the nanowires have good optical properties. The core-shell nanowire was then fabricated into single nanowire field effect transistor by standard e-beam photolithography. Electrical measurements reveals that the p-type ZnO/ZnTe FET device has a turn on voltage of -1.65 V and the hole mobility is 13.3 cm2/V s.

Type-II Core/Shell Nanowire Heterostructures and Their Photovoltaic Applications

“…Therefore, type-II coaxial solar cells, acting as multi-junction solar cells, are potential to be full-spectrum cells by the modulation of composition, structure, and interface. Many studies have been made from worldwide research groups in type-II coaxial nanowire growth and photovoltaic applications [52][53][54][55][56][57][58]. Zhang's group fabricated the vertically aligned ZnO/ZnSe and ZnO/ZnS core/shell NWAs by CVD method [42,59], and investigated the photovoltaic effect of the ZnO/ZnS NWA.…”

“…Lim's group also grew ZnO/ZnSe core/shell NWAs by successive ionic layer adsorption and reaction method, and develops a photovoltatic device with an overall conversion efficiency of 1.37% [56]. Chang's group synthesized ZnO/ZnTe core/shell NWAs on an a-plane sapphire substrate by CVD and metal-organic chemical deposition [58]. Despite of so many studies, the predicted longer wavelength transitions at type-II interface has not been convincingly observed.…”