Exciton Absorption, Photoluminescence and Band Structure of N-Free and N-Doped In(1-x)Ga(x)P.

摘要

Optical absorption data on In(1-x)Ga(x)P are reported showing the first observation of the exciton absorption peak in a III-V ternary alloy. This allows the most accurate determination to date of both the composition dependence of the gamma band gap and the position of gamma -X crossover. Absorption and photoluminescence spectra are compared for both direct and indirect In(1-x)Ga(x)P. In addition, absorption, photoluminescence, and luminescence lifetimes of In(1-x)Ga(x)P:N are examined. These data suggest that the A-line is perturbed by alloy disorder and forms a broad luminescence band for < or = 0.94. The observed Stokes shift for the N-trap in the alloy is characteristic of an impurity strongly coupled to the lattice. The temperature dependence of the N luminescence band if sound to be well described by the conventional configuration-coordinate model for phonon-coupled impurity luminescence. Implications of these results for light emitting devices are mentioned.