Nanostructure-enhanced Broadband Photodetector Based on Graphene/CdSe Quantum Dot/Silicon Multiple Junctions

• Main Authors: Zhan, Jun-Yu, 詹竣宇
• Other Authors: Lin, Tai-Yuan
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/83937728306479422712

碩士 === 國立臺灣海洋大學 === 光電科學研究所 === 102 === The thesis studies the fabrication of efficient broadband(380 nm ~ 940 nm) photodetector(PD) base on graphene/CdSe QDs/Si multiple junctions. At 2 V bias for the graphene side, the external quantum efficiency(EQE) up to 218 % at 510 nm and the responsivity as high as 0.9 A/W for the range from 520 nm to 660 nm were achieved. The response time and recovery time are 0.24 ms and 0.28 ms, respectively. Under bias of -2 V for the graphene side, the dark current, photocurrent and on/off ratio was fou- nd to be 1.77#westeur024#10-6 A, 2.06#westeur024#10-4 A and ~10+2, respectively. It was found that when CdSe QDs were added, the EQE and responsivity of graphene/CdSe QDs/Si PD with respect to that of graphene/Si PD were enhanced together with the increase in the absorption band of the detector ranging from ultraviolet to near-infrared. Thus the graphene/CdSe QDs/Si multiple junctions can form the efficient broadband phtodetector.