title: Universal Strategy To Reduce Noise Current for Sensitive Organic Photodetectors.
abstract: Low noise current is critical for achieving high-detectivity organic photodetectors. Inserting charge-blocking layers is an effective approach to suppress the reverse-biased dark current. However, in solution-processed organic photodetectors, the charge-transport material needs to be dissolved in solvents that do not dissolve the underneath light-absorbing layer, which is not always possible for all kinds of light-absorbing materials developed. Here, we introduce a universal strategy of transfer-printing a conjugated polymer, poly(3-hexylthiophene) (P3HT), as the electron-blocking layer to realize highly sensitive photodetectors. The transfer-printed P3HT layers substantially and universally reduced the reverse-biased dark current by about 3 orders of magnitude for various photodetectors with different active layers. These photodetectors can detect the light signal as weak as several picowatts per square centimeter, and the device detectivity is over 1012Jones. The results suggest that the strategy of transfer-printing P3HT films as the electron-blocking layer is universal and effective for the fabrication of sensitive organic photodetectors.
authors.affiliation: Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Sixing
authors.initials: S
authors.lastname: Xiong
authors.affiliation: Department of Mechanical and Materials Engineering, Nebraska Center for Materials and Nanoscience, University of Nebraska , Lincoln, Nebraska 68588-0656, United States.
authors.forename: Lingliang
authors.initials: L
authors.lastname: Li
authors.affiliation: Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Qin
authors.affiliation: Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Mao
authors.affiliation: Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Bangwu
authors.initials: B
authors.lastname: Luo
authors.affiliation: Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Youyu
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Zaifang
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Mechanical and Materials Engineering, Nebraska Center for Materials and Nanoscience, University of Nebraska , Lincoln, Nebraska 68588-0656, United States.
authors.forename: Jinsong
authors.identifier: http://orcid.org/0000-0002-0509-8778
authors.initials: J
authors.lastname: Huang
authors.affiliation: Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Yinhua
authors.identifier: http://orcid.org/0000-0001-6424-9962
authors.initials: Y
authors.lastname: Zhou
keywords: electron-blocking layer; organic photodetectors; solution processing; suppressing dark current; transfer printing