posted on 2013-12-26, 00:00authored byKwang-Hee Lee, Dong-Seok Leem, Jeffrey S. Castrucci, Kyung-Bae Park, Xavier Bulliard, Kyu-Sik Kim, Yong Wan Jin, Sangyoon Lee, Timothy P. Bender, Soo Young Park
Green-sensitive
organic photodetectors (OPDs) with high sensitivity
and spectral selectivity using boron subphthalocyanine chloride (SubPc)
derivatives are reported. The OPDs composed of SubPc and dicyanovinyl
terthiophene derivative (DCV3T) demonstrated the highest green-sensitivity
with maximum external quantum efficiency (EQE) of 62.6 % at an applied
voltage of −5 V, but wide full-width-at-half-maximum (FWHM)
of 211 nm. The optimized performance considering spectral selectivity
was achieved from the composition of N,N-dimethyl quinacridone (DMQA) and SubPc showing the high specific
detectivity (D*) of 2.34 × 1012 cm
Hz1/2/W, the EQE value of 60.1% at −5 V, and narrow
FWHM of 131 nm. In spite of the sharp absorption property of SubPc
with the maximum wavelength (λmax) at 586 nm, the
EQE spectrum showed favorable green-sensitivity characterized by smooth
waveform with λmax at 560 nm, which is induced from
the high reflectance of SubPc centered at 605 nm. The photoresponsivity
of the OPD devices was found to be consistent with their absorptance.
Optimized DMQA/SubPc device showed the lowest value of blue crosstalk
(0.42) and moderate red crosstalk (0.37), suggesting its promising
application as a green-sensitive OPD.