High performance surface plasmon enhanced ZnO-Pt @ AlN core shell UV photodetector synthesized by magnetron sputtering

ZnO, a potential optoelectronic material, is attracting significant attention in ultraviolet (UV) photodetectors. However, low photoelectric conversion efficiency is a shortcoming because of its surface defect. In this paper, a plasmonic enhanced high speed UV photodetector was fabricated by ZnO-Pt@AlN core shell nanowires arrays using chemical vapor deposition (CVD) and magnetron sputtering methods. As shown in experiment results, the core shell nanowire arrays exhibit 3.7 times enhancement of UV emission and inhibition of visible emission by surface defect. In addition, compared to the pure ZnO nanorod array detector, the introduction of Pt nanoparticles and AlN shell layer resulted in a device with faster rising and falling edges (from 5.67 s to 3.09 s; from 41.18 to 0.32 s) as well as higher bright-to-dark current ratio (from 6.6 to 310.5). As shown in simulation results, the optical field would be localized in the shell of ZnO nanorods, and the ZnO-Pt@AlN core-shell structure can effectively improve the absorption of 365 nm UV light. In one word, this paper employs two general methods to improve the optoelectronic performance of ZnO, and obtains plasmonic enhanced high speed UV photodetector fabricated by ZnO-Pt@AlN core shell nanowires array as well as the mechanism of enhancement is explained.