Concentration dependence of the absorption coefficient fornminus; andpminus;type GaAs between 1.3 and 1.6 eV

摘要

The absorption coefficient agr; for GaAs at room temperature was determined in the spectral range from 1.3 to 1.6 eV by transmission measurements for 10les;agr;les;103cmminus;1and by a Kramersminus;Kronig analysis of the reflectance for agr;gsim;103cmminus;1. Measurements were made on highminus;puritynminus;type samples,nminus;type samples with freeminus;electron concentrations from 5times;1016to 6.7times;1018cmminus;3,pminus;type samples with freeminus;hole concentrations from 1.5times;1016to 1.6times;1019cmminus;3, andpminus;type samples heavily doped with the amphoteric impurity Si. These data show that near the direct energy gapEgthe shape of the agr;minus;vsminus;photonminus;energy curve is strongly dependent on the impurity concentration.