Application of the nanosphere on MgZnO metal-semiconductor-metal ultraviolet photodetector

• Main Authors: Meng-Ju Lee, 李孟儒
• Other Authors: Wu-Yih Uen
• Format: Others
• Language: en_US
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/d5864w

碩士 === 中原大學 === 電子工程研究所 === 101 === In this study, atomic layer deposition (ALD) system was used to deposit the Mg0.1Zn0.9O films as the absorption layer of the metal-semiconductor-metal ultraviolet photodetectors (MSM-UPDs). The photoelectrochemical (PEC) method was used to form a passivation layer Zn(OH)2 on the surface of the Mg0.1Zn0.9O films, which can reduce the dangling bonds and surface states on the surface of Mg0.1Zn0.9O films, which could reduce the dark current and improve low frequency noise of the Mg0.1Zn0.9O MSM-UPDs. At bias of 5 V, the dark current of the Mg0.1Zn0.9O MSM-UPDs with PEC passivation decreased from 1.81×10-9 A to 1.53×10-10 A; then devices were illuminated by incident light wavelength of 340 nm, and the light power of 39.98 μW, the ultraviolet (UV)-visible rejection ratio increased from 1.71×103 to 5.50×103, and the NEP decreased from 6.18×10-13 W to 4.27×10-13 W. Compared with the MSM-UPDs with the PEC passivation, the UV-visible rejection ratio of the MSM-UPDs with the PEC passivation and silica nanospheres anti-reflection layer could effectively increase from the 5.50×103 to 1.44×104 and the NEP could decrease from 4.27×10-13 W to 2.60×10-13 W. It was attributed to that the surface state and dangling bond were effectively passivated using PEC method, and the amount of incident light was increased by the silica nanospheres anti-reflection layer. The detectivity of the Mg0.1Zn0.9O MSM-UPDs with and without PEC passivation and Mg0.1Zn0.9O MSM-UPDs with PEC passivation and silica nanospheres coating were 5.11×1011cmHz1/2W-1、7.39×1011cmHz1/2W-1及1.21×1012cmHz1/2W-1, respectively.