Feasibility of enhancing the thermoelectric power factor in GaNxAs1-x

This study was motivated by the possibility of using N resonant levels interacting with the GaAs conduction band, in GaNxAs1-x (0 < x < 2.5%), to enhance the density of states effective mass (m(d)) and consequently the thermoelectric power factor (S-2 sigma)-where S is the Seebeck coefficient and sigma is the electrical conductivity. However, it was observed that, compared with GaAs, the power factor was reduced in spite of a small increase in the m(d). The influences of carrier passivation and dopant type, as well as the changes in the carrier scattering mechanism, which degrades the carrier mobility, are discussed.