Thermoelectric and Photoelectric Effects of 2D Bismuth for Flexible Electronics

Two-dimensional (2D) bismuth has received increasing research attention due to tunable small bandgap. This work explored the electrical and thermal property of 2D bismuth grown on silicon and polyimide substrates by molecular beam epitaxy (MBE) and electron beam evaporation. 2D bismuth exhibited superior mechanical flexibility, and tunable electrical property via thickness and interface control. E-beam evaporated 2D bismuth could yield Seebeck coefficient and electrical conductivity comparable to MBE counterparts. There is an enhanced thermoelectric performance for e-beam evaporated 2D bismuth on polyimide (PI) than silicon substrates. Our results suggest 2D bismuth with photoelectric and thermoelectric effects holds great promise for flexible sensors and energy devices.