Mechanism of Excellent Photoelectric Characteristics in Mixed-Phase ZnMgO Ultraviolet Photodetectors with Single Cutoff Wavelength.
Mixed-phase ZnMgO (m-ZMO) thin films with a single absorption edge tuning from ∼3.9 to ∼4.8 eV were realized on a-face sapphire (a-Al2O3) by plasma-assisted molecular beam epitaxy. The small lattice mismatch of both ZnO and MgO with a-Al2O3 should be responsible for the single and controllable absorption edge. Metal-semiconductor-metal (MSM) photodetectors were fabricated based on these m-ZMO films, and the devices have the single cutoff wavelength, which can be tuned from 335 to 275 nm. These devices possess low dark current (78 pA for m-Z0.67M0.33O, 11 pA for m-Z0.59M0.41O, and 4 pA for m-Z0.39M0.61O at 40 V) and high responsivity (434 A/W for m-Z0.67M0.33O, 89.8 A/W for m-Z0.59M0.41O, and 3.7 A/W for m-Z0.39M0.61O at 40 V). Further response study reveals that the 90-10% decay time of m-Z0.67M0.33O, m-Z0.59M0.41O, and m-Z0.39M0.61O is around 37, 30, and 0.7 ms, respectively. Large amounts of heterojunction interfaces between wurtzite ZMO and cubic rock-salt ZMO could be responsible for the low dark current and high responsivity of our mixed-phase devices. The excellent comprehensive performance of m-ZMO UV photodetectors on a-Al2O3 suggests that m-ZMO UV photodetectors should have great applied potential.
State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Dongnanhu Road 3888, Changchun, 130033, People's Republic of China.|University of Chinese Academy of Sciences , Beijing, 100049, People's Republic of China.|College of Physics and Optoelectronics, Taiyuan University of Technology , Taiyuan, 030024, People's Republic of China.
Ming-Ming
MM
Fan
State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Dongnanhu Road 3888, Changchun, 130033, People's Republic of China.
Ke-Wei
KW
Liu
State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Dongnanhu Road 3888, Changchun, 130033, People's Republic of China.
Xing
X
Chen
State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Dongnanhu Road 3888, Changchun, 130033, People's Republic of China.|University of Chinese Academy of Sciences , Beijing, 100049, People's Republic of China.
Xiao
X
Wang
State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Dongnanhu Road 3888, Changchun, 130033, People's Republic of China.
Zhen-Zhong
ZZ
Zhang
State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Dongnanhu Road 3888, Changchun, 130033, People's Republic of China.
Bing-Hui
BH
Li
State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Dongnanhu Road 3888, Changchun, 130033, People's Republic of China.
De-Zhen
DZ
Shen
heterojunction interfaces; high responsivity; high-performance; low dark current; mixed-phase ZnMgO; photodetectors