An experimental investigation on the effective electron mass in InGaO3(ZnO)3 by valence electron energy-loss spectroscopy

Abstract

In2−xGaxO3(ZnO)m are reported to exhibit an extremely high field-effect mobility, and therefore considered as the potential channel materials for transparent field-effect transistor. To gain a deep insight into the high mobility of In2−xGaxO3(ZnO)m, the effective electron mass, which is inherently related to the mobility of charge carriers as well as the density of states, is investigated by valence electron energy-loss spectroscopy. The effective electron masses in InGaO3(ZnO)3 nanobelts with the incident electron beam along the c axis and <112-0> are determined as 0.130m0 and 0.132m0, respectively. These results critically checked by a comparison with calculated values and values measured by others. It not only well validates the results acquired from theoretical investigations, but also shed a new light on the isotropy of the effective electron mass in InGaO3(ZnO)m.