Mechanisms of Forward Current and Reverse Leakage Current in GaN-Based Blue Light Emitting Diodes

Abstract

By measuring the current-voltage (I-V) characteristics in the temperature range of 100 K to 300 K, mechanisms of the forward tunneling current and the reverse leakage current of GaN-based blue light emitting diodes are analyzed. For the forward current, both the temperature-independent current slope and an ideality factor larger than 2 are typical features of the defect-assisted tunneling mechanism. For the reverse leakage current, the linear relationship between I and (V+Vbi)1/2 indicates a hopping conduction mechanism at low bias, while the power law I-V relationship suggests that the space charge limited current dominates the reverse leakage current at high bias.