posted on 2021-08-23, 16:41authored byZiyuan Li, Simeon Trendafilov, Fanlu Zhang, Monica S. Allen, Jeffery W. Allen, Sukrith U. Dev, Wenwu Pan, Yang Yu, Qian Gao, Xiaoming Yuan, Inseok Yang, Yi Zhu, Anha Bhat, Sherry X. Peng, Wen Lei, Hark Hoe Tan, Chennupati Jagadish, Lan Fu
Highly
compact, filter-free multispectral photodetectors have important
applications in biological imaging, face recognition, and remote sensing.
In this work, we demonstrate room-temperature wavelength-selective
multipixel photodetectors based on GaAs0.94Sb0.06 nanowire arrays grown by metalorganic vapor phase epitaxy, providing
more than 10 light detection channels covering both visible and near-infrared
ranges without using any optical filters. The nanowire array geometry-related
tunable spectral photoresponse has been demonstrated both theoretically
and experimentally and shown to be originated from the strong and
tunable resonance modes that are supported in the GaAsSb array nanowires.
High responsivity and detectivity (up to 44.9 A/W and 1.2 × 1012 cm √Hz/W at 1 V, respectively) were obtained from
the array photodetectors, enabling high-resolution RGB color imaging
by applying such a nanowire array based single pixel imager. The results
indicate that our filter-free wavelength-selective GaAsSb nanowire
array photodetectors are promising candidates for the development
of future high-quality multispectral imagers.