Author(s): Gao, YQ (Gao, Yaqi); Yang, JK (Yang, Jiankun); Ji, XL (Ji, Xiaoli); He, R (He, Rui); Yan, JC (Yan, Jianchang); Wang, JX (Wang, Junxi); Wei, TB (Wei, Tongbo)

Source: ACS APPLIED MATERIALS & INTERFACES Volume: 14 Issue: 18 Pages: 21232-21241 DOI: 10.1021/acsami.2c03636 Published: APR 29 2022

Abstract: The high-quality semipolar (11 (2) over bar2) AlGaN epitaxial films have been obtained on m-plane sapphire by metal-organic chemical vapor deposition. X-ray rocking curve measurements show the full-width at half-maximums of semipolar (11 (2) over bar2)-oriented AlGaN films are 0.357 degrees and 0.531 degrees along [11 (23) over bar](AlGaN) and [1 (1) over bar 00](AlGaN), respectively. The fabricated semipolar AlGaN metal-semiconductor-metal solar-blind ultraviolet (UV) photodetector (PD) exhibits a high responsivity of 1842 A/W. The fast response and reliability of the UV PD are ensured via fast switching with a rise and decay time of 90 ms and 53(720) ms, respectively. The UV PD exhibits a significant reduction in the dark current, that is, from 100 mu A to 780 fA at 10 V, using a simple wet chemical etching to modify the surface properties of materials. The photo-to-dark-current ratio value of the etched UV PD reaches 4 orders of magnitude higher than the unetched UV PD under 270 nm illumination. These are attributed to the fact that KOH wet etching assists in eliminating the surface states and reconstructing the surface oxides. This work might provide a new potential for the development of solar-blind UV PDs with high performance.

Accession Number: WOS:000813108500001

PubMed ID: 35486957

ISSN: 1944-8244

eISSN: 1944-8252

Full Text: https://pubs.acs.org/doi/10.1021/acsami.2c03636