title: Achieving EQE of 16,700% in P3HT:PC71BM based photodetectors by trap-assisted photomultiplication.
abstract: We report a trap-assisted photomultiplication (PM) phenomenon in solution-processed polymer photodetectors (PPDs) based on P3HT:PC71BM as the active layer, the maximum EQE of 16,700% is obtained for the PPDs with PC71BM doping weight ratio of 1%. The PM phenomenon is attributed to the enhanced hole tunneling injection assisted by trapped electrons in PC71BM near Al cathode, which can be demonstrated by the transient photocurrent curves and EQE spectra of PPDs with different PC71BM doping ratios. The positive effect of trapped electrons in PC71BM near Al cathode on the hole tunneling injection is further confirmed by the simulated optical field and exciton generation rate distributions in the active layer and the EQE spectra of PPDs with Al(1)/P3HT:PC71BM(100:1)/Al(2) device structure under forward and reverse biases. This discovery may open a new road for organic materials to be used in highly sensitive photodetectors while preserving the advantages of organic materials.
authors.affiliation: Key Laboratory of Luminescence and Optical Information, Ministry of Education, Beijing Jiaotong University, Beijing 100044, People's Republic of China.
authors.forename: Lingliang
authors.initials: L
authors.lastname: Li
authors.affiliation: Key Laboratory of Luminescence and Optical Information, Ministry of Education, Beijing Jiaotong University, Beijing 100044, People's Republic of China.
authors.forename: Fujun
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Luminescence and Optical Information, Ministry of Education, Beijing Jiaotong University, Beijing 100044, People's Republic of China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Luminescence and Optical Information, Ministry of Education, Beijing Jiaotong University, Beijing 100044, People's Republic of China.
authors.forename: Qiaoshi
authors.initials: Q
authors.lastname: An
authors.affiliation: Key Laboratory of Luminescence and Optical Information, Ministry of Education, Beijing Jiaotong University, Beijing 100044, People's Republic of China.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Sun
authors.affiliation: Key Laboratory of Luminescence and Optical Information, Ministry of Education, Beijing Jiaotong University, Beijing 100044, People's Republic of China.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Catalysis, Dalian institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Luminescence and Optical Information, Ministry of Education, Beijing Jiaotong University, Beijing 100044, People's Republic of China.
authors.forename: Feng
authors.initials: F
authors.lastname: Teng