The preparation and semiconducting properties of single crystals of ZnSnAs"2 compound B

Large single crystals of a semiconducting inter-metallic compound ZnSnAs"2 have been grown by Bridgman method. Their electrical and optical properties have been studied as a function of temperature.Single crystals of ZnSnAs"2 show p-type conductivity and cleave on the (110) plane. For sing...
Ausführliche Beschreibung

Large single crystals of a semiconducting inter-metallic compound ZnSnAs"2 have been grown by Bridgman method. Their electrical and optical properties have been studied as a function of temperature.Single crystals of ZnSnAs"2 show p-type conductivity and cleave on the (110) plane. For single crystals having the chalcopyrite structure, a hole mobility of 130 cm^2/V-sec and a carrier concentration of 1.2 x 10^1^8/cm^3 are observed at room temperature. From the slope of the intrinsic resistivity, the width of the forbidden energy gap is estimated to be 0.59 eV at 0^oK. The mobility ratios found by the usual procedure from the Hall coefficient maximum and determined from the resistivity data by the method derived by Hunter are 9 and 12, respectively. From the Seebeck coefficient data for 296^oK and 557^oK, the effective mass of holes is calculated to be 0.43m"0 and 0.59m"0 respectively, and the relaxation time is found to be 2.6 x 10^-^1^4 sec at 296^oK. The infrared absorption edge gives an estimate of 0.66 eV for the energy gap for direct transitions at room temperature, and extrapolation of the results for the temperature range from 88^oK to 296^oK gives a value of 0.74 eV at 0^oK. For the disordered zinc-blende structure, a resistivity of the order of 10^-^3 Ω-cm and a carrier concentration of the order of 10^1^9/cm^3 are obtained at room temperature. Ausführliche Beschreibung