Electronic Raman scattering of the negative charge state of the 78-meV double acceptor in GaAs

Intracenter 1${\mathrm{S}}_{3/2}$(${\mathrm{\Gamma }}_8$)-2${\mathrm{S}}_{3/2}$(${\mathrm{\Gamma }}_8$ ) electronic Raman scattering has been observed from the negative charge state of the 78-meV double acceptor that is commonly found in GaAs grown by the liquid-encapsulated Czochralski technique. The magnitude of this transition energy is identical to the separation between the photoluminescence bands that involve this double acceptor and occur at 1.441- and 1.283 eV. This observation indicates that both the 1.441 and 1.283-eV emission bands arise from the capture of an electron by the neutral charge state of the 78-meV double acceptor. The higher- or lower-energy emission bands occur when the hole bound to the negative charge state of this double acceptor occupied either the 1$S_{3/2}$(${\Gamma }_8$) or 2$S_{3/2}$(${\Gamma }_8$) hydrogenic states, respectively. Because a similar relationship should be observed between emission bands involving other double acceptors, the observation of such a relationship for an unidentified shallow acceptor provides strong evidence for its double-acceptor nature.