Self-reassembly wearable thermoelectric generator using surface-modified TMDCs

Wearable thermoelectric generators (WTEGs) are of significance in the conversion of body heat into electricity for the purpose of powering wearable electronic devices. Two-dimensional (2D) transition metal dichalcogenides (TMDCs) exhibit exceptional thermoelectric power factors and mechanical stability, making them promising flexible thermoelectric materials. However, the output voltage of the present TMDC-based WTEGs remains at a relatively low level. In this study, we precisely modulate the electronic structure of titanium disulfide (TiS2) nanosheets in a restacked film by surface modification, leading to the decoupling phenomenon of a simultaneous rise in the electrical conductivity and the Seebeck coefficient. This method enhances the thermoelectric power factor by approximately 14 times compared to pre-modified samples. We fabricated a flexible self-reassembly WTEG using 1T-phase molybdenum disulfide (MoS2) nanosheets as p-type material and modified TiS2 nanosheets as an n-type material. The generator achieved a voltage output of approximately 15 mV while harvesting heat from the human arm, showcasing its potential for practical applications.