Great Enhancement Effect of 20–40 nm Ag NPs on Solar-Blind UV Response of the Mixed-Phase MgZnO Detector

Abstract

High-performance solar-blind UV detector with high response and fast speed is needed in multiple types of areas, which is hard to achieve in one device with a simple structure and device fabrication process. Here, the effects of Ag nanoparticles (NPs) with different sizes on UV response characteristics of the device are studied, the Ag NPs with different sizes that are made from a simple vacuum anneal method. Ag NPs with different sizes could modulate the peak response position of the mixed-phase MgZnO detector from near UV range (350 nm) to deep UV range (235 nm), and the enhancement effect of the Ag NPs on the UV response differs much with the crystal structure and the basic UV response of the MgZnO thin film. When high density 20–40 nm Ag NPs is induced, the deep UV (235 nm) response of the mixed-phase MgZnO detector is increased by 226 times, the I uv / I dark ratio of the modified device is increased by 17.5 times. The slight enhancement in UV light intensity from 20 to 40 nm Ag NPs induces multiple tunnel breakdown phenomena within the mixed-phase MgZnO thin film, which is the main reason for the abnormal great enhancement effect on deep UV response of the device, so the recovery speed of the modified device is not influenced. Therefore, Ag NPs with different sizes could effectively modulate the UV response peak position of mixed-phase MgZnO thin films, and the introduction of Ag NPs with high density and small size is a simple way to greatly increase the sensitivity of the mixed-phase MgZnO detector at deep UV light without decreasing the device speed.

High performance solar-blind UV detector with Mg0.472Zn0.528O/Mg0.447Zn0.553O double layer structure on MgO substrate

“…Liu et al have made MSM structure mix-phase MgZnO detector with 191 A W −1 response at 250 nm deep UV light [16]. Our group have made relative system study on the crystal structure and orientation of MgZnO thin films under different deposition condition with Mg 0.4 Zn 0.6 O and Mg 0.3 Zn 0.7 O source targets [20][21][22][23][24], and the mix-phase MgZnO detector with 96 A W −1 response at 250 nm deep UV light have been made under 500 °C low temperature with Mg 0.3 Zn 0.7 O source target [20]. Recently, multiple types of new device structure, such as MOSFET, heterojunction, 2DEG structure, have been induced to improve the performance of Solar-blind UV detectors [25][26][27][28][29].…”

A UVC photodetector based on Mg-doped ZnO film

“…Solar-blind ultraviolet (UV) photodetector (PD) can nd extensive applications in re prevention, ozone hole monitoring, navigation, and more, for the UVC (200-280 nm) PD is interference-free in low UVC radiation zones in the near-earth environment [1][2][3][4][5][6][7][8]. Because detecting UVC requires wide bandgap semiconductors as the photosensitive layer, UVC PDs are mainly made from ultra-wide bandgap semiconductors (UWBG), such as gallium oxide (Ga 2 O 3 ), aluminum nitride (AlN), boron nitride (BN), and magnesium-doped zinc oxide (MgZnO) [1,[9][10][11][12].…”