Bound Exciton, Free‐To‐Bound and Electron‐Hole Plasma Luminescence in Ga x In 1− x P (0.54 ≦ x ≦ 0.76)

The luminescence of Ga x In 1− x P (0.54 ≦ x ≦ 0.76) at 4.2 K is investigated. At high excitation intensities an electron‐hole plasma is observed in the sample with composition x = 0.54 and possibly in that with x = 0.74. No signs of an electron‐hole liquid are found in any of the samples studied. At low excitation intensities the luminescence spectrum is dominated by bound exciton transitions for samples with x = 0.76, 0.74, and 0.54 and by donor‐acceptor pair emission. For the sample with near crossover composition the spectrum is dominated by free‐to‐bound transitions. The results are discussed considering alloy disorder and are compared to those obtained in GaAs 1− x P x and Ga 1− x Al x As under high excitation.