Improving thermoelectric properties of Cu2O powder via interface modification

Abstract

We report thermoelectric properties of Cu2O powder through interface modification. Seebeck coefficient (SC) of Cu2O–Au composite powder was measured to be 900–1500 μV/K in the temperature range of 300–420 K, and power factor was ∼1.95 μW/m⋅K2 at 420 K, in contrast to raw Cu2O powder (0.86 μW/m⋅K2). The improved Seebeck coefficient and power factor relate very likely to the band structure modification by Au atoms, energy filtering and remote doping. Optic measurement and band structure calculated using density functional theory confirmed the band gap of Cu2O–Au composite powder (1.78eV) is slightly narrower than the raw Cu2O powder (1.85eV) and higher electronic density of states (DOS) in the conductance band of Cu2O–Au composite powder. Powder form thermoelectric devices (P-TE) easily prepared by pressing in a die without sintering might offer an alternative paradigm for mass fabrication with low cost. The high Seebeck coefficient and power factor of P-TE could find applications as power generator, temperature/touch sensors, transient thermoelectric coolers, etc.