A review of leakage current mechanism in nitride based light emitting diode

Abstract

We review the dominant mechanism and characteristics of it which gave rise to the existence of forward and reverse leakage current in nitride based light emitting diode (LED). LED is one of the promising device to be used as a lighting source because it does not contain mercury unlike fluorescent lamps. However, the existence of leakage current can affect the reliability and efficiency of LED. Hence, its importance to understand the mechanism that responsible for its existence. The occurrence of leakage current is divided into three main parameters: 1) low bias; 2) medium or high bias; 3) temperature dependence. In low reverse bias, Poole-Frenkel is the dominant mechanism while tunneling is the dominant mechanism in high bias region. Furthermore, in forward bias, defect assisted tunneling is most likely the dominant mechanism. In low forward bias, electrons are the dominant carriers in defect assisted tunneling while in medium forward bias, holes are the dominant carriers.  Moreover, Variable Range Hopping (VRH) is reported to be dominant when the temperature of conduction is below 200K.