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High-performance (Al0.4Ga0.6)2O3/Al0.32Ga0.68N-based UVC/UVB tunable dual-band photodetectors.
- Source :
- CrystEngComm; 5/21/2024, Vol. 26 Issue 19, p2551-2559, 9p
- Publication Year :
- 2024
-
Abstract
- The detection of ultraviolet B (UVB) and UVC radiation is of paramount importance, and has expanding applications in industrial, scientific, environmental and biomedical fields. In this work, high-Al-content β-(Al<subscript>0.4</subscript>Ga<subscript>0.6</subscript>)<subscript>2</subscript>O<subscript>3</subscript>/Al<subscript>0.32</subscript>Ga<subscript>0.68</subscript>N films prepared via a thermal oxidation process from AlGaN layers are employed to fabricate UVC/UVB dual-band photodetectors (PDs). The PDs achieve two responsivity peaks at ∼200 nm and 305 nm, and also exhibit tunable dual-band photodetection, which can operate in separate UVB-dominated, UVC/UVB broadband and UVC-dominated detection modes by modulating the bias voltage from 10 V to 25 V. In particular, the PDs exhibit a responsivity (R) of 0.35 A W<superscript>−1</superscript>, detectivity of 2.46 × 10<superscript>12</superscript> Jones, UVC/UVA rejection ratio (R<subscript>200</subscript>/R<subscript>365</subscript>) of 70 and UVC/visible rejection ratio (R<subscript>200</subscript>/R<subscript>500</subscript>) of 106 with an external quantum efficiency of 219% under 200 nm light illumination at 25 V bias, demonstrating good comprehensive performance over the UVC band. The tunable dual-band detection capability can be ascribed to the effect of increasing bias voltage on lowering the barrier height between electrodes and the (Al<subscript>x</subscript>Ga<subscript>1−x</subscript>)<subscript>2</subscript>O<subscript>3</subscript> layer, promoting the photogenerated electrons in (Al<subscript>x</subscript>Ga<subscript>1−x</subscript>)<subscript>2</subscript>O<subscript>3</subscript> films to easily cross over the reduced barrier height and contributing to the UVC detection. In addition to providing a facile, economical and feasible way to fabricate UVC/UVB tunable dual-band PDs via bias voltage regulation, this work is also expected to inspire further exploration on developing versatile and high-performance multi-band PDs. [ABSTRACT FROM AUTHOR]
- Subjects :
- PHOTODETECTORS
QUANTUM efficiency
VOLTAGE
Subjects
Details
- Language :
- English
- ISSN :
- 14668033
- Volume :
- 26
- Issue :
- 19
- Database :
- Complementary Index
- Journal :
- CrystEngComm
- Publication Type :
- Academic Journal
- Accession number :
- 177400737
- Full Text :
- https://doi.org/10.1039/d3ce01297b