Optimization of large power factor in molybdenum oxide thin films deposited on Si substrate

Abstract

The performance of thermoelectric (TE) thin films strongly depends on the substrates. In our previous study, we investigated the power factor (PF) 1.78 mW/[Formula: see text] at 700 K in [Formula: see text] thin film grown on single crystalline Si, comparable to the state of art in other TE thin films. Such boosted PF originates mainly from the significantly enhanced Seebeck coefficient, correlated with the contribution of the Si substrate. In this paper, the PF has been prominently optimized up to 12.5 mW/[Formula: see text] at 668 K by adjusting the thickness of [Formula: see text] film in the [Formula: see text]/Si system, which could be understood in the frame work of parallel slab model. Experimentally, the effective TE properties were susceptible to the substrate–film interface. The existence of Mo in [Formula: see text] film might limit the formation of [Formula: see text] interfacial layer. These results suggest a simple, low-cost, scalable technique route to explore highly effective TE devices.