Electron transport in a GaPSb film
1 Graduate Institute of Applied Physics, National Taiwan University, Taipei, 106, Taiwan
2 Department of Physics, National Taiwan University, Taipei, 106, Taiwan
3 Graduate Institute of Electronics Engineering, National Taiwan University, Taipei , 106, Taiwan
4 Department of Electrical Engineering, National Taiwan University, Taipei, 106, Taiwan
5 Electronics Testing Center, No. 8, Lane 29, Guishan Shiang, Taoyuan County, Taiwan, 333
Nanoscale Research Letters 2012, 7:640 doi:10.1186/1556-276X-7-640Published: 23 November 2012
We have performed transport measurements on a gallium phosphide antimonide (GaPSb) film grown on GaAs. At low temperatures (T), transport is governed by three-dimensional Mott variable range hopping (VRH) due to strong localization. Therefore, electron–electron interactions are not significant in GaPSb. With increasing T, the coexistence of VRH conduction and the activated behavior with a gap of 20 meV is found. The fact that the measured gap is comparable to the thermal broadening at room temperature (approximately 25 meV) demonstrates that electrons can be thermally activated in an intrinsic GaPSb film. Moreover, the observed carrier density dependence on temperature also supports the coexistence of VRH and the activated behavior. It is shown that the carriers are delocalized either with increasing temperature or magnetic field in GaPSb. Our new experimental results provide important information regarding GaPSb which may well lay the foundation for possible GaPSb-based device applications such as in high-electron-mobility transistor and heterojunction bipolar transistors.