Electrically Driven Light Emission from Individual CdSe Nanowires

TL;DR

This study demonstrates electroluminescence from individual CdSe nanowires in three-terminal devices, revealing that light emission occurs near the contact due to potential drops and Schottky barriers, advancing understanding of nanoscale optoelectronic behavior.

Contribution

It provides detailed optical and electrical characterization of electroluminescence in individual CdSe nanowires, highlighting the role of contact interfaces and potential profiles in light emission.

Findings

EL occurs near the positively biased contact

Potential drops sharply at the EL site

Schottky barrier influences emission mechanism

Abstract

We report electroluminescence (EL) measurements carried out on three-terminal devices incorporating individual n-type CdSe nanowires. Simultaneous optical and electrical measurements reveal that EL occurs near the contact between the nanowire and a positively biased electrode or drain. The surface potential profile, obtained by using Kelvin probe microscopy, shows an abrupt potential drop near the position of the EL spot, while the band profile obtained from scanning photocurrent microscopy indicates the existence of an n-type Schottky barrier at the interface. These observations indicate that light emission occurs through a hole leakage or an inelastic scattering induced by the rapid potential drop at the nanowire-electrode interface.