Effect of Device Package on Optical, Spectral, and Thermal Properties of InGaN/GaN Near-Ultraviolet Lateral Light-Emitting Diodes

We investigated the package effect on the temperature-dependent optical and spectral characteristics of InGaN/GaN near-ultraviolet (NUV) lateral light-emitting diodes (LLEDs) on the metal heat sink (MH) and package (PKG) in the injection current range of 0 - 500 mA at 298 and 358 K. For the NUV LLEDs on the MH, the device characteristics reflected directly its chip performance. For the NUV LLEDs on the PKG, the rapidly varied spectral shift as well as the reduced device efficiency was observed due to the increased number of layers with relatively low thermal conductivities. The junction temperature (Tj ) and thermal resistance of the NUV LLEDs on the PKG were also significantly increased compared to the NUV LLEDs on the MH. The three-dimensional heat transfer simulations for both the devices were carried out to obtain the temperature distributions by finite element method. The theoretically calculated Tj values showed a good agreement with the experimentally measured Tj values