Optical and electrophysical properties of GaAs(O):Cr
Аннотация
The elemental composition of GaAs(O):Cr was determined using energy-dispersive spectroscopy and found to be: gallium 47.71 at.%, arsenic 44.37 at.%, chromium 0.10 at.%, and oxygen 7.82 at.%. The material was found to possess a cubic crystal structure (space group F43m) with a lattice parameter of a = 5.6538 Å and an average crystallite size of 44.24 nm. Raman spectroscopy revealed peaks at 159, 196, 252, 277, 328, 349, 411, 500 cm−1, corresponding to phonon modes in GaAs(O):Cr and their modifications due to the presence of oxygen andchromium dopants. These observations indicate that doping has a significant effect on the vibrational properties of the crystal lattice. Fourier-transform infrared spectroscopy identified local vibrational modes at 578, 620, 717, 733, 758, 815, 946 cm−1, attributed to optical phononexcitations. The specific electrical resistivities, as well as the temperature dependences of carrier mobility and carrier concentration, were measured over the temperature range of 100–300 K.