High-Performance AlGaN Heterojunction Phototransistor With Dopant-Free Polarization-Doped P-Base

Carrier transport modulation in InGaN/GaN multi quantum wells using polarization engineering for high-performance visible-light photodetection

“…Next, a 75-nm-thick graded AlxGa1-xN (x=0~0.12) layer was grown for avoiding the strain relaxation between the former uid-GaN and the next growth layer. Then, a 150-nm-thick AlGaN layer with Al composition varying linearly from 12% to 0% was deposited as a polarization induced p-type layer, 17 followed by a 21-period uid-InGaN(3 nm QW)/GaN(8 nm QB) MQW visible-light absorber layer. Finally, a 150-nm-thick heavily Si-doped n + -GaN (n~3×10 18 cm -3 ) was grown as n-type ohmic-contact layer.…”

Progress on photovoltaic AlGaN photodiodes for solar-blind ultraviolet photodetection

“…In addition, they also proposed that indium surfactant possibly triggers the stronger valence-band modulation, thereby further facilitating the decrease of AE and the increase of hole concentration. Sun et al reported a kind of p-type polarization-doping method without using dopant in the AlGaN heterojunction phototransistor [77] . The strong polarization effect in AlGaN makes the p-type bulk doping possible with forming 3D hole gas induced by graded negative polarization [78] .…”

Realizing high zero-bias gain in a GaN-based bipolar phototransistor through thin-base configuration for ultraviolet imaging

“…[13][14][15][16] Thereafter, researchers have reported considerable optimizations in the doping or structure of GaN-based BPTs. 11,[17][18][19] Additionally, some investigations have shown that GaN-based BPTs can operate in an avalanche mode. [20][21][22] Although GaN-based HPTs can realize high gain, it is worth emphasizing that both photocurrent and optical gains remain relatively low when external bias falls below the knee voltage.…”