Back to Search Start Over

The mechanism of photogenerated minority carrier movement in organic phototransistors

Authors :
Chunzhi Jiang
Xiaoyi Huang
Tao Han
Gui Jin
Kun Cao
Linshan Sun
Shufang Ding
Qirui Feng
Source :
Journal of Materials Chemistry C. 8:12284-12290
Publication Year :
2020
Publisher :
Royal Society of Chemistry (RSC), 2020.

Abstract

The acceptor phase, which affects the free carrier transport by trapping the photogenerated minority carrier in the active layer, plays an important role in organic phototransistors (OPTs) based on a bulk heterojunction (BHJ). In this work, the FBT-Th4(1,4):PC61BM blend film with high mobility is selected as the active layer to construct the OPT. A model of the action of minority carrier movement on hole transmission is established by using the change rule of device performance under different donor/acceptor ratios. This model is tested and validated using PTB7:PC61BM-based OPT with low mobility. The results show that a continuous transmission channel of photogenerated minority carrier tends to form in the OPT under high concentration doping, which increases the probability that a minority carrier would recombine with the holes, leading to poor device performance. These results can provide practical guidance for the preparation of high-performance OPT devices. The optimized FBT-Th4(1,4) : PC61BM device with a low D/A ratio (∼10 : 1) obtained shows ultrahigh photoelectric detection performance (gain = 4.7 × 105, D* = 1.4 × 1016 Jones).

Details

ISSN :
20507534 and 20507526
Volume :
8
Database :
OpenAIRE
Journal :
Journal of Materials Chemistry C
Accession number :
edsair.doi...........0dc53a505fcffd1effc6863e4ae9432c
Full Text :
https://doi.org/10.1039/d0tc02698k