“…However, the composition at which the crossover occurs is hard to determine. It is because of its proximity and because of the presence of the long-range ordering effect in In x Ga 1Àx P. A low-temperature band gap energy of 2.018 eV was reported for fully disordered InGaP lattice matched to GaAs [1]. Although the highest theoretically proposed value of the ordering-induced band gap reduction is about 470 meV, the real experimental value is in the range of 100 meV.…”