Device-level electro-thermal co-optimization of the InP based terahertz sources

This study employs a systematic numerical investigation framework centered on TCAD simulation to address thermal management challenges in InP-based In_0.53Ga_0.47As planar Gunn diodes. Through comprehensive two-dimensional thermal-electrical co-simulation, we evaluate substrate materials (InP, Si, diamond) and thermal films (diamond, graphene) on device performance. The simulation results indicate that the diamond substrate can significantly reduce the operating temperature of the device, increase the oscillation frequency, and enhance the output power. Both diamond and graphene thermal films effectively mitigate thermal resistance, improving output characteristics through temperature reduction exceeding 150 K. Furthermore, we propose a novel diamond-graphene composite thermal management structure that achieves a significant temperature reduction from 607.3 K to 373.3 K (ΔT = 234 K), simultaneously enhancing oscillation frequency to 203.6 GHz and power conversion efficiency to 0.80%. These findings establish material-driven thermal optimization principles for high-frequency terahertz sources, suggesting significant potential for device performance enhancement.