Electrical characteristics and photodetection mechanism of TiO₂/AlGaN/GaN heterostructure-based ultraviolet detectors with a Schottky junction

Electrical characteristics and photodetection mechanism of TiO₂/AlGaN/GaN heterostructure-based ultraviolet detectors with a Schottky junction

Zhan, Teng (Chinese Academy of Sciences; University of Chinese Academy of Sciences)
Sun, J. (TU Delft Electronic Components, Technology and Materials; Tsinghua University)
Feng, Tao (Chinese Academy of Sciences; University of Chinese Academy of Sciences)
Zhang, Yulong (Tsinghua University)
Zhou, Binru (Chinese Academy of Sciences; University of Chinese Academy of Sciences)
Zhang, Banghong (Chinese Academy of Sciences; University of Chinese Academy of Sciences)
Wang, Junxi (Chinese Academy of Sciences; University of Chinese Academy of Sciences)
Sarro, Pasqualina M (TU Delft Electronic Components, Technology and Materials)
Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials)

2022

Recent research focusing on wide-bandgap and two-dimensional materials with a Schottky junction has provided a new concept for ultraviolet photodetectors. However, the working mechanism of the Schottky junction-based detector varies depending on the photosensitive materials used and the device structure. We demonstrated a TiO₂/AlGaN/GaN heterostructure-based photodetector with a Schottky junction, integrating an ultraviolet photosensitive TiO₂ nanolayer, a two-dimensional electron gas (2DEG) field effect transistor, and a metal-semiconductor Schottky diode. The spectral response wavelength region of the detector is 200-365 nm and the peak responsivity is 37.396 A W⁻¹ at −5 V bias under 240 nm UV illumination, respectively. Meanwhile, a peak photo-to-dark current ratio (PDCR) of 5.1 × 10² at −2 V bias voltage was observed under 274 nm UV irradiation. This Schottky-based 2DEG heterostructure detector can realize three dominant working principles: (i) the Schottky emission mechanism at a low reverse voltage (0-1 V) before the current is fully turned on, (ii) the Poole-Frenkel emission mechanism at a medium reverse voltage (−1 to −2 V) with peak PDCR, and (iii) the Fowler-Nordheim tunneling mechanism at a high reverse voltage (>−2 V) with a high responsivity. Continuous cycle response measurement results indicate that the detectors have good response repeatability and reliability. The characteristics of response wavelength, responsivity, and stability show that the detector can be used for several commercial applications, including sunscreen UV monitoring and LED sterilization light source detection.

http://resolver.tudelft.nl/uuid:667d438c-de8e-411b-84b6-7d9102118bb6

https://doi.org/10.1039/d2tc04491a

2023-06-19

2050-7526

Journal of Materials Chemistry C: materials for optical and electronic devices, 11 (2023) (5), 1704-1713

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Correction: https://doi.org/10.1039/D2TC04491A

Institutional Repository

journal article

© 2022 Teng Zhan, J. Sun, Tao Feng, Yulong Zhang, Binru Zhou, Banghong Zhang, Junxi Wang, Pasqualina M Sarro, Kouchi Zhang, More Authors