Oriented Bi2Te3-based films enabled high performance planar thermoelectric cooling device for hot spot elimination
Guoying Dong, Jianghe Feng, Guojuan Qiu, Yuxuan Yang, Qiyong Chen, Yang Xiong, Haijun Wu, Yifeng Ling, Lili Xi, Long Chen, Jibao Lu, Yixin Qiao, Guijuan Li, Juan Li, Ruiheng Liu, Rong Sun
Abstract
Film-thermoelectric cooling devices are expected to provide a promising active thermal management solution with the continues increase of the power density of integrated circuit chips and other electronic devices. However, because the microstructure-related performance of thermoelectric films has not been perfectly matched with the device configuration, the potential of planar devices on chip heat dissipation has still not been fully exploited. Here, by liquid Te assistant growth method, highly (00 l) orientated Bi2Te3-based films which is comparable to single crystals are obtained in polycrystal films in this work. The high mobility stem from high orientation and low lattice thermal conductivity resulting from excess Te induced staggered stacking faults leads to high in-plane zT values ~1.53 and ~1.10 for P-type Bi0.4Sb1.6Te3 and N-type Bi2Te3 films, respectively. The planar devices basing on the geometrically designed high orientation films produce a remarkable temperature reduction of ~8.2 K in the hot spot elimination experiment, demonstrating the great benefit of Te assistant growth method for oriented planar Bi2Te3 films and planar devices devices design, and also bring great enlightenment to the next generation active thermal management for integrated circuits. The authors fabricate highly (00l) orientated Bi2Te3-based films by liquid Te assistant growth method, showing high mobility stemming from high orientation and low lattice thermal conductivity, resulting from excess Te induced staggered stacking faults.