Impact of Channel Thickness and Doping Concentration for Normally-Off Operation in Sn-Doped ß-Ga2O3 Phototransistors.
Sensors (Basel)
; 24(17)2024 Sep 07.
Article
en En
| MEDLINE
| ID: mdl-39275733
ABSTRACT
We demonstrate a Sn-doped monoclinic gallium oxide (ß-Ga2O3)-based deep ultraviolet (DUV) phototransistor with high area coverage and manufacturing efficiency. The threshold voltage (VT) switches between negative and positive depending on the ß-Ga2O3 channel thickness and doping concentration. Channel depletion and Ga diffusion during manufacturing significantly influence device characteristics, as validated through computer-aided design (TCAD) simulations, which agree with the experimental results. We achieved enhancement-mode (e-mode) operation in <10 nm-thick channels, enabling a zero VG to achieve a low dark current (1.84 pA) in a fully depleted equilibrium. Quantum confinement in thin ß-Ga2O3 layers enhances UV detection (down to 210 nm) by widening the band gap. Compared with bulk materials, dimensionally constrained optical absorption reduces electron-phonon interactions and phonon scattering, leading to faster optical responses. Decreasing ß-Ga2O3 channel thickness reduces VT and VG, enhancing power efficiency, dark current, and the photo-to-dark current ratio under dark and illuminated conditions. These results can guide the fabrication of tailored Ga2O3-based DUV phototransistors.
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01-internacional
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MEDLINE
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En
Revista:
Sensors (Basel)
Año:
2024
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Article
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Suiza