High-performance nano-Schottky diodes and Nano-MESFETs made on single CdS nanobelts

Nano-Schottky diodes and nanometal-semiconductor field-effect transistors (MESFETs) on single CdS nanobelts (NBs) have been fabricated and studied. The Au/CdS NB Schottky diodes have very low reverse current density (similar to 3.0 x 10(-5) A center dot cm(-2) at -10 V reverse bias) and the highest on/off current ratio (similar to 10(8)) reported so far for nano-Schottky diodes. The single CdS NB MESFETs exhibit n-channel normally on (depletion) mode, low threshold voltage (similar to-1.56 V), high transconductance (similar to 3.5 mu S), low subthreshold swing (similar to 45 mV/dec), and the highest on/off current ratio (similar to 2 x 10(8)) reported so far for nanofield-effect transistors. We also show that the absolute value of threshold voltage for a metal-insulator-semiconductor field-effect transistor made on a single CdS NB can be reduced from similar to 12.5 to similar to 0.4 V and its transconductance can be increased from similar to 0.2 to similar to 3.2 mu S by adding an extra Au Schottky contact on the CdS NB, the mechanism of which is discussed.