Investigation of Junction Thermal Characteristics of Light-Emitting Transistors

Self-heating effect is the main contribution to the junction temperature in bipolar junction transistors. In this paper, the dc temperature-variation measurement and extraction method, including thermal-electric feedback coefficient of an InGaP/GaAs light-emitting transistor (LET), are presented. The thermal-electric feedback coefficient of the LET is -2.07 mV/K at collector current of 2 mA and the thermal resistance is 993.3°C/W when the corresponding power dissipation is 44.19 mW. The thermal properties of the conventional heterojunciton bipolar transistor is also demonstrated and compared. The differences can be attributed to the quantum-well thermionic emission mechanisms and enhanced radiative recombination in the LET.