Effect of Barrier Temperature on Photoelectric Properties of GaN-Based Yellow LEDs*

Abstract

The effect of growth temperature of barriers on photoelectric properties of GaN-based yellow light emitting diodes (LEDs) is investigated. It is found that as the barrier temperature increases, the crystal quality of multi-quantum wells (MQWs) and the quality of well/barrier interface are improved, and the quantum well is thermally annealed, so that the indium atoms in the quantum well migrate to the equilibrium position, reducing the phase separation of the quantum well and improving the crystal quality of quantum wells (QWs). However, the external quantum efficiency (EQE) of the samples begins to decrease when raising the barrier temperature even further. One explanation may be that the higher barrier temperature destroys the local state in the quantum well and reduces the well/barrier interface quality. Therefore, a suitable barrier temperature is proposed, contributing to the improvement of the luminous efficiency of the yellow LEDs.