Correlation between p-GaN growth environment with electrical and optical properties of blue LEDs

摘要

Two blue (450 nm) light-emitting diodes (LED), which only differ in top p-GaN layer growth conditions, were comparatively investigated. I-V, C-V, TLM, Electroluminescence (EL) and Photoluminescence (PL) techniques were applied to clarify a correlation between MOCVD carrier gas and internal properties. The A-structure grown in the pure N_2 environment demonstrated better parameters than the B-structure grown in the N_2/H_2 (1:1) gas mixture. The mixed growth atmosphere leaded to an increase of sheet resistances of p-GaN layer. EL and PL measurements confirmed the advantage of the pure N_2 utilization, and C(V_R) measurement pointed the increase of static charge concentration near the p-GaN interface in the B structure.