Photoluminescence Study of Carbon Doped Gallium Arsenide

The photoluminescence studies of the carbon doped epitaxial gallium arsenide revealed that a pair of emission bands at 1.493 eV (B-A) and 1.490 eV (D-A) were attributed to the carbon acceptor on arsenic site. The sharp doublet emission lines at 1.5127 eV and 1.4937 eV were identified with the exciton recombination bound to a neutral carbon acceptor and the two-hole transition in which the neutral carbon acceptor is left in an excited state, respectively. From the observation of these emissions, the 1 S 3/2 ground and 2 S 3/2 excited state energies of carbon acceptor were found to be 26.5 meV and 7.5 meV above the valence band edge, respectively. The results were supported by the effective mass arguments and by the dependence of the binding energy on the atomic number of impurities.