Terahertz impurity luminescence under the interband photoexcitation of semiconductors

The observation of intense terahertz luminescence under the interband photoexcitation of n-GaAs and p-Ge semiconductors at low temperatures is reported. The terahertz photoluminescence is caused by radiative transitions, which accompany the capture of nonequilibrium carriers by impurity centers. These centers are in turn created in the crystal due to the impurity-assisted electron-hole recombination. The external quantum yield of the luminescence reaches 0.1%.