am6b16788_si_001.pdf (457.42 kB)
Universal Strategy To Reduce Noise Current for Sensitive Organic Photodetectors
journal contribution
posted on 2017-02-22, 00:00 authored by Sixing Xiong, Lingliang Li, Fei Qin, Lin Mao, Bangwu Luo, Youyu Jiang, Zaifang Li, Jinsong Huang, Yinhua ZhouLow 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 1012 Jones. 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.