Design Optimization of Micro-Thermoelectric Cooler for Thermal Management using Finite Element Simulations

Thermal Management is a key factor for optimizing the reliable performance of miniaturized optoelectronic devices. Excessive heat flux compromises the wavelength stability of the laser and directly affects the device performance, explicitly at the micro-nano scale. Therefore, advanced photonic devices require a precise thermal management system for instant heat dissipation. Micro-thermoelectric coolers (µ-TECs) offer effective practical options for thermal management in compact photonic devices because of their active cooling and precise controllability. The cooling performance of these µ-TECs is related to the efficiency of the thermoelectric materials used to build, as well as their device architecture. As for minimizing the size of the photonic system, design optimization of the µ-TEC is required for its easy integration. In this work, we studied and analyzed the geometrical structure to optimize the design of the µ-TEC with realistic boundary conditions including electrical contact resistance. Finite element model simulations are performed using COMSOL multi-physics software. The effect of various geometrical parameters (i.e. leg height, cross-sectional area, top contact metal and fill factor) on the cooling performance of the µ-TEC are examined. The results indicate that the device's electrical and thermal resistance is affected by geometrical parameters, which leads to variation in a temperature gradient in the device. The shorter leg height of 10–20 µm with a larger cross-sectional area, with optimum top contact and fill factor improves the device performance known as coefficient of performance (COP). The COP has increased from 0.059 to 0.067 (~13%) upon enlarging the cross-section area of the p-type leg by 4 times as compared to n-type leg. All these results should be taken into consideration to fabricate a full µ-TEC for the thermal management of photonic integrated devices and circuits.