Low dark current broadband 360-1650 nm ITO/Ag/n-Si Schottky photodetectors

• Published in: Optics express 2018-03, Vol.26 (5), p.5827-5834
• Main Authors: Huang, Zhiwei, Mao, Yichen, Lin, Guangyang, Yi, Xiaohui, Chang, Ailing, Li, Cheng, Chen, Songyan, Huang, Wei, Wang, Jianyuan
• Format: Article
• Language: English
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/OE.26.005827

This work designed an ITO/Ag/n-Si Schottky photodetector with broad wavelength detection and low dark current. The introduction of Ag interfacial layer and post rapid thermal annealing dramatically increase the barrier height of ITO/n-Si Schottky diode by 0.32 eV, leading to the 2300 × reduction of dark current. A well-behaved ITO/Ag (8 nm)/n-Si Schottky diode with a high rectification ratio ( ± 1 V) of 4 × 10 and low dark current (-1 V) of 9.2 nA was achieved. Such low dark current device spontaneously provides high sensitivity for visible/near infrared wavelength detection, in which substantial responsivity for wavelengths from 360 to 1650 nm was realized through both inter-band and internal photoemission. The design here provides an encouraging strategy for monolithically integrated pure Si photodetectors operating at long wavelength up to 1650 nm.