Photoconductivity of Single-crystalline Selenium Nanotubes

TL;DR

This study investigates the photoconductivity of single-crystalline selenium nanotubes, revealing their potential as efficient photo-sensors and solar cell materials due to their high photoconductivity and tunable barrier properties.

Contribution

It presents a novel two-terminal device setup for measuring photoconductivity of SCSNT at room temperature and demonstrates their superior photoconductive properties compared to other nanotubes.

Findings

Schottky barriers form with W and Au contacts, influenced by light intensity.

Sharp switching behavior observed below a certain illumination threshold.

High photoconductivity of 0.59 Ohm·cm^-1, surpassing other nanotubes.

Abstract

Photoconductivity of single-crystalline selenium nanotubes (SCSNT) under a range of illumination intensities of a 633nm laser is carried out with a novel two terminal device arrangement at room temperature. It's found that SCSNT forms Schottky barriers with the W and Au contacts, and the barrier height is a function of the light intensities. In low illumination regime below 1.46x10E-4 muWmum-2, the Au-Se-W hybrid structure exhibits sharp switch on/off behavior, and the turn-on voltages decrease with increasing illuminating intensities. In the high illumination regime above 7x10E-4 muWmum-2, the device exhibits ohmic conductance with a photoconductivity as high as 0.59Ohmcm-1, significantly higher that reported values for carbon and GaN nanotubes. This finding suggests that SCSNT is potentially a good photo-sensor material as well we a very effective solar cell material.