Open AccessResponsivity improvement of Ti–diamond–Ti structured UV photodetector through photocurrent gain
Author(s) -
Zhangcheng Liu,
Dan Zhao,
JinPing Ao,
Xiaohui Chang,
Yanfeng Wang,
Jiao Fu
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.017092
Subject(s) - responsivity , photocurrent , materials science , photodetector , optoelectronics , diamond , ultraviolet , optics , schottky barrier , photoconductivity , physics , diode , composite material
In this study, a Ti-diamond-Ti structured ultraviolet photodetector was fabricated on a homoepitaxial diamond layer with an oxygen-terminated surface. The properties of the Ti/diamond schottky contact were measured using X-ray photoelectron spectroscopy, and the barrier height was found to be 1.15 eV. At a bias of 3 V, the responsivity at 210 nm was only 4.29 mA/W, while at 12 V, the responsivity increased rapidly to 51 mA/W. The increase can be ascribed to the photocurrent gain. With the further increase in voltage, an avalanche effect was produced, and the responsivity could reach 1.18 A/W at 50 V. Moreover, the transient response behavior of the photodetector exhibited a good repeatability and response speed.