Fabrication and characterization of GaN-based light-emitting diodes without pre-activation of p-type GaN

Abstract

We fabricated GaN-based light-emitting diodes (LEDs) without pre-activation of p-type GaN. During the fabrication process, a 100-nm-thick indium tin oxide film was served as the p-type contact layer and annealed at 500°C in N2 ambient for 20 min to increase its transparency as well as to activate the p-type GaN. The electrical measurements showed that the LEDs were featured by a lower forward voltage and higher wall-plug efficiency in comparison with LEDs using pre-activation of p-type GaN. We discussed the mechanism of activation of p-type GaN at 500°C in N2 ambient. Furthermore, x-ray photoemission spectroscopy examinations were carried out to study the improved electrical performances of the LEDs without pre-activation of p-type GaN.

P-type Doping of Broad-band Nitride Semiconductors

“…have been rapidly developed, began to enter the commercial market. [26][27] In general, the achievements in P-GaN research in recent years can be roughly divided into the following categories: [28][29][30][31][32][33][34][35][36][37][38][39][40][41] Hull and Chung et al studied the role of O 2 in the annealing atmosphere during P-GaN annealing. Among them, the latter compared the effect of annealing in N 2 atmosphere with annealing temperature Nakagawa et al also studied the annealing of P-GaN films under N 2 and O 2 atmospheres, and replaced the H in the NH3 atmosphere of the epitaxial layer cooling process with deuterium (D).…”