Signature of nonreciprocal Seebeck effect in 2D ferroelectric semiconductor α-In 2 Se 3

Abstract Nonreciprocal transport phenomena, indicating that forward and backward flows are inequivalent, have been studied mainly in terms of electric conduction in low-symmetry conductors. Although a similar nonreciprocal transport is expected for thermoelectric transport, that is, the Seebeck effect, its experimental studies on bulk crystals are still rare. Herein, we aim to obtain an experimental signature of the nonreciprocal Seebeck effect in the layered ferroelectric semiconductor α-In 2 Se 3 . Thermoelectric voltage signals induced by sinusoidal heater current (sinωt) include cos2ωt and cos4ωt contributions, the ratios and signs of which are consistent with the expected trends of the nonreciprocal Seebeck effect.