Temperature of 618 and 1250℃ at As and Ga sities respectively in the horizontal Bridgman furnace and growht speed of 0.7cm/h were found to be optimal for the production of single crystalline GaAs. Self-seeded and unintentionally doped GaAs crystals ...
Temperature of 618 and 1250℃ at As and Ga sities respectively in the horizontal Bridgman furnace and growht speed of 0.7cm/h were found to be optimal for the production of single crystalline GaAs. Self-seeded and unintentionally doped GaAs crystals showd n-type characteristics with Hall mobillity of ∼0.75㎡/V-sec and carrier density of ∼10^19 m^-3 when the mesurements were made right after the growth. About three month later it was found that the same samples were converted to p-type GaAs. The analysis on the p-type sample showed that impurity scattering is dominant at around room temperature and thus the measured Hall mobility was 0.0065㎡/V-sec at 300K. 7.4±0.6 eV was obtained for acoustic deformation potential in the heavy hole band by fitting the theoretical conductivity and Hall coefficient to the corresponding experimental data. The value is very much higher than the theoretically estimated value, 3.6eV. The carrier density variation with temperature obtained from the present analysis gave 0.38 and 0.17 eV respectively for the activation energies of donor and acceptor.