In:
Advanced Optical Materials, Wiley, Vol. 10, No. 7 ( 2022-04)
Abstract:
This work reports the fabrication of high performance solar‐blind deep‐UV photodetectors using (In x Ga 1 − x ) 2 O 3 thin films grown on Al 2 O 3 (0001) substrates. The In contents in (In x Ga 1 − x ) 2 O 3 are controlled at x = 0, 0.1 and 0.2, whereas a higher In content leads to phase segregation of Ga 2 O 3 and In 2 O 3 . The bandgaps of (In x Ga 1 − x ) 2 O 3 films are tuned from 4.93 eV for Ga 2 O 3 to 4.67 eV for (In 0.2 Ga 0.8 ) 2 O 3 . Schottky‐type photodetectors based on metal−semiconductor−metal structure were fabricated. The (In 0.1 Ga 0.9 ) 2 O 3 photodetector is highly sensitive to solar‐blind UV spectrum and achieves a large on/off current ratio of over 10 8 , a remarkable specific detectivity of 4.5 × 10 16 Jones with a prominent responsivity of 23.3 A W − 1 . Such enhanced performance compared to Ga 2 O 3 is associated with In modulated optical and electronic properties. High‐resolution X‐ray photoemission spectroscopy was used to study the interfacial electronic structure at the semiconductor−metal interface. A large Schottky barrier height of 1.31 eV was found for (In 0.1 Ga 0.9 ) 2 O 3 devices, accounting for the low dark current. More importantly, the incorporation of In introduces In 4 d states hybridizing with O 2 p at top of the valence band of (In 0.1 Ga 0.9 ) 2 O 3 , which increases the optical absorption to generate a higher density of photocarriers, and therefore results in greater photocurrents.
Type of Medium:
Online Resource
ISSN:
2195-1071
,
2195-1071
DOI:
10.1002/adom.202102138
Language:
English
Publisher:
Wiley
Publication Date:
2022
detail.hit.zdb_id:
2708158-8
