Title :
Sensitivity Enhancement of Ultraviolet Photodetectors With the Structure of p-NiO/Insulator-SiO2/n-ZnO Nanowires
Author :
Yu-Ren Li ; Chung-Yun Wan ; Chia-Tsung Chang ; Yu-Chih Huang ; Wan-Lin Tsai ; I-Che Lee ; Huang-Chung Cheng
Author_Institution :
Dept. of Electron. Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan
Abstract :
A high-performance photodetector with the structure of NiO/SiO2/ZnO nanowires has been proposed. The devices with 6-nm-thick SiO2 exhibited a better rectification ratio (Jforward/Jreverse) of 246 at ±2 V, lower dark current density (Jdark) of 3.5 × 10-7 A/cm2 at a reverse bias of 2 V, and superior ultraviolet (UV) sensitivity (IUV/Idark) of 16.23 than those without the SiO2 layer (Jforward/Jreverse = 44, Jdark = 4.7 × 10-6 A/cm2, and IUV/Idark = 5.5). The improved performance was mainly due to the ultrathin inserted SiO2 layer that builds a barrier height to minimize the transmission probability of low-energy carriers, leading to the enhancement of the UV sensing characteristics.
Keywords :
II-VI semiconductors; insulation; nanosensors; nanowires; nickel compounds; photodetectors; probability; silicon compounds; ultraviolet detectors; wide band gap semiconductors; zinc compounds; NiO-SiO2-ZnO; UV sensing characteristics; dark current density; low-energy carrier; p-NiO-insulator-SiO2-n-ZnO nanowire; sensitivity enhancement; size 6 nm; transmission probability; ultrathin inserted layer; ultraviolet photodetector; voltage 2 V; Current density; II-VI semiconductor materials; Nanowires; Photodetectors; Sensitivity; Zinc oxide; Heterojunctions; Nickel Oxide (NiO); Photodetectors; Zinc Oxide (ZnO); heterojunctions; nickel oxide (NiO); zinc oxide (ZnO);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2015.2448721
