Crystal synthesis, electrical properties, and spontaneous and stimulated photoluminescence of In1−xGaxP:N grown from solution

The growth of In1−xGaxP from solution at constant temperature is described, and the distribution coefficient and incorporation of Ga in the crystal and also donor impurities are discussed. The variation of the measured mobility with composition indicates that the direct-indirect transition is near x=0.74. Photoluminescence data on direct and indirect In1−xGaxP:N are presented, and the energies of the band gap, nitrogen A line, and NN-pair peaks are plotted as a function of crystal composition. The nitrogen A line (EN) is degenerate with the Γ conduction-band minimum (EΓ) at a crystal composition of x ∼0.71. For x≤0.71 a resonant N-trap state exists above the fundamental conduction band edge. The resonant N-trap transition can be photoexcited into laser operation in x=0.69 In1−xGaxP:N at very high energy (2.246 eV–5520 Å, 77 °K) where, in fact, the recombination transition is enhanced (EN∼EΓ).