title: Ultrasensitive and Highly Selective Photodetections of UV-A Rays Based on Individual Bicrystalline GaN Nanowire.
abstract: The detection of UV-A rays (wavelength of 320-400 nm) using functional semiconductor nanostructures is of great importance in either fundamental research or technological applications. In this work, we report the catalytic synthesis of peculiar bicrystalline GaN nanowires and their utilization for building high-performance optoelectronic nanodevices. The as-prepared UV-A photodetector based on individual bicrystalline GaN nanowire demonstrates a fast photoresponse time (144 ms), a high wavelength selectivity (UV-A light response only), an ultrahigh photoresponsivity of 1.74 × 107A/W and EQE of 6.08 × 109%, a sensitivity of 2 × 104%, and a very large on/off ratio of more than two orders, as well as robust photocurrent stability (photocurrent fluctuation of less than 7% among 4000 s), showing predominant advantages in comparison with other peer semiconductor photodetectors. The outstanding optoelectronic performance of the bicrystalline GaN nanowire UV-A photodetector is further analyzed based on a detailed high-resolution transmission electron microscope (HRTEM) study, and the two separated crystal domains within the GaN nanowires are believed to provide separated and rapid carrier transfer channels. This work paves a solid way toward the integration of high-performance optoelectronic nanodevices based on bicrystalline or horizontally aligned one-dimensional semiconductor nanostructures.
authors.affiliation: Shenyang National Laboratory for Materials Science (SYNL), Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) , No. 72 Wenhua Road, Shenyang 110016 China.
authors.forename: Xinglai
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Shenyang National Laboratory for Materials Science (SYNL), Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) , No. 72 Wenhua Road, Shenyang 110016 China.
authors.forename: Baodan
authors.identifier: http://orcid.org/0000-0001-8141-8940
authors.initials: B
authors.lastname: Liu
authors.affiliation: Shenyang National Laboratory for Materials Science (SYNL), Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) , No. 72 Wenhua Road, Shenyang 110016 China.
authors.forename: Qingyun
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Shenyang National Laboratory for Materials Science (SYNL), Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) , No. 72 Wenhua Road, Shenyang 110016 China.
authors.forename: Wenjin
authors.initials: W
authors.lastname: Yang
authors.affiliation: Department of Physics, Beijing Normal University , 100875, Beijing, P. R. China.
authors.forename: Changmin
authors.initials: C
authors.lastname: Xiong
authors.affiliation: Shenyang National Laboratory for Materials Science (SYNL), Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) , No. 72 Wenhua Road, Shenyang 110016 China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: Shenyang National Laboratory for Materials Science (SYNL), Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) , No. 72 Wenhua Road, Shenyang 110016 China.
authors.forename: Xin
authors.initials: X
authors.lastname: Jiang
keywords: GaN; HRTEM; UV-A ray; bicrystalline nanowires; photodetectors