Thermal Conductivity of GaAs and GaAs1−xPx Laser Semiconductors

Measurements of thermal conductivity for the range 3° to 300°K are reported for both pure and heavily doped n- and p-type GaAs single crystals, and n-type heavily doped polycrystalline GaAs1−xPx crystals with six compositions between x=0 and x=0.5. The alloy ingots have much lower K values due to alloy scattering, with a composition of 35% phosphide content (near the limit of laser operation) having a K less than 1/20 that of pure GaAs at 77°K. Hence heat dissipation is a serious obstacle to continuous operation of alloy lasers.