Efficient solar-driven photothermoelectric generator facilitated by carbon dots aggregates

Abstract

The energy crisis is a significant issue that the world is facing in the 21st century. Thermoelectric energy transfer emerges as a promising solution that can convert heat energy into electric energy. However, there remains a big challenge that the efficient utilization of light energy to achieve continuous electricity ultimately. The red emitting carbon dots (RCDs) could self-assemble into the aggregates (ARCDs) via cooperative solvophobic effect combined with hydrogen bonding interaction, which exhibits considerably enhanced absorption with excellent photothermal conversion effect (PCE ≈ 62%) compared to its dispersed state. Moreover, these aggregates were then loaded onto semiconductors to create solar-driven photothermoelectric generator (LHE), with unprecedented output efficiency (V_output ≈ 5000 mV, I_output ≈ 25 mA, and P_output ≈ 123 mW), which can easily charge smartphones outdoors. This work offers a supramolecular chemistry perspective for the construction of CDs aggregates and presents an sustainable approach towards achieving continuous photothermoelectric energy transfer.