Weak-Light-Enhanced AlGaN/GaN UV Phototransistors with a Buried p-GaN Structure
Guardado en:
| Publicado en: | Electronics vol. 14, no. 10 (2025), p. 2076 |
|---|---|
| Autor principal: | |
| Otros Autores: | , , , , , , , , |
| Publicado: |
MDPI AG
|
| Materias: | |
| Acceso en línea: | Citation/Abstract Full Text + Graphics Full Text - PDF |
| Etiquetas: |
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| Resumen: | We propose a novel ultraviolet (UV) phototransistor (PT) architecture based on an AlGaN/GaN high electron mobility transistor (HEMT) with a buried p-GaN layer. In the dark, the polarization-induced two-dimensional electron gas (2DEG) at the AlGaN/GaN heterojunction interface is depleted by the buried p-GaN and the conduction channel is closed. Under UV illumination, the depletion region shrinks to just beneath the AlGaN/GaN interface and the 2DEG recovers. The retraction distance of the depletion region during device turn-on operation is comparable to the thickness of the AlGaN barrier layer, which is an order of magnitude smaller than that in the conventional p-GaN/AlGaN/GaN PT, whose retraction distance spans the entire GaN channel layer. Consequently, the proposed device demonstrates significantly enhanced weak-light detection capability and improved switching speed. Silvaco Atlas simulations reveal that under a weak UV intensity of 100 nW/cm2, the proposed device achieves a photocurrent density of 1.68 × 10−3 mA/mm, responsivity of 8.41 × 105 A/W, photo-to-dark-current ratio of 2.0 × 108, UV-to-visible rejection ratio exceeding 108, detectivity above 1 × 1019 cm·Hz1/2/W, and response time of 0.41/0.41 ns. The electron concentration distributions, conduction band variations, and 2DEG recovery behaviors in both the conventional and novel structures under dark and weak UV illumination are investigated in depth via simulations. |
|---|---|
| ISSN: | 2079-9292 |
| DOI: | 10.3390/electronics14102076 |
| Fuente: | Advanced Technologies & Aerospace Database |