Polarization Enhanced GaN Avalanche Photodiodes With p-type In_0.05Ga_0.95N Layer

Abstract

In this letter, novel heterostructure p-in GaN avalanche photodiodes (APDs) with p-type In 0.05 Ga 0.95 N layer are proposed and analyzed through Silvaco Atlas simulations. The introduction of the In 0.05 Ga 0.95 N layer generates a negative polarization charge at the pIn 0.05 Ga 0.95 N/i-GaN heterojunction interface via the piezoelectric polarization effect. Three times higher hole concentration in the pIn 0.05 Ga 0.95 N layer is obtained due to the smaller activation energy of the Mg dopant. Induced polarization charge and increased hole concentration work together to reduce the voltage drop in the pIn 0.05 Ga 0.95 N layer and enhance the electric field intensity in the i-GaN layer. The calculated results show that the heterostructure APD demonstrates a reduced operating voltage of more than 26 V and an improved multiplication gain by an order of magnitude in comparison to the conventional one.

Simulation Study on the Structure Design of p-GaN/AlGaN/GaN HEMT-Based Ultraviolet Phototransistors

“…Steady-state 2-D numerical simulations based on Silvaco TCAD Atlas software are performed. The definition of fundamental equations and physical models can be found in our previous work [18]. The spaces between the gate source and gate drain are filled with SiO 2 .…”