Trap-assisted photomultiplication polymer photodetectors obtaining an external quantum efficiency of 37,500%

Lingliang Li; Fujun Zhang; Wenbin Wang; Qiaoshi An; Jian Wang; Qianqian Sun; Miao Zhang

doi:10.1021/acsami.5b00041

Trap-assisted photomultiplication polymer photodetectors obtaining an external quantum efficiency of 37,500%

ACS Appl Mater Interfaces. 2015 Mar 18;7(10):5890-7. doi: 10.1021/acsami.5b00041. Epub 2015 Mar 4.

Authors

Lingliang Li¹, Fujun Zhang¹, Wenbin Wang¹, Qiaoshi An¹, Jian Wang¹, Qianqian Sun¹, Miao Zhang¹

Affiliation

¹ †Key Laboratory of Luminescence and Optical Information, Ministry of Education, Beijing Jiaotong University, Beijing 100044, People's Republic of China.

PMID: 25715745
DOI: 10.1021/acsami.5b00041

Abstract

A smart strategy is reported to obtain photomultiplication (PM) type polymer photodetectors (PPDs) based on poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) which are commonly used in polymer solar cells. The PPDs with 1 wt % PC61BM exhibit a champion EQE of 37,500% under 625 nm illumination with an intensity of 8.87 μW cm(-2) at -19 V bias. The PM phenomenon of PPDs with rather low PC61BM doping ratios should be attributed to the enhanced hole tunneling injection assisted by trapped electrons in PC61BM near the Al cathode, which can be completely demonstrated from (i) turning distribution of electron traps by changing P3HT:PC61BM doping weight ratios from 200:1 to 1:1; (ii) adjusting interfacial barrier width by inserting LiF layer between the active layer and the Al cathode.

Keywords: band bending; organic photodetector; photomultiplication; trap; tunneling injection.

Publication types

Research Support, Non-U.S. Gov't