Optical properties of gas source MBE grown AlInP on GaAs

Optical properties of silicon (Si) doped AlxIn1−xP grown by gas source molecular beam epitaxy (GSMBE) have been investigated by using photoluminescence (PL). The PL peaks of AlxIn1−xP shift to higher energy side as Al mole fraction increases in direct bandgap region, and the fractions of strained portion have been calculated. Results also show that for direct bandgap AlxIn1−xP both band-to-band (B–B) and donor-to-acceptor (D–A) transition peaks exist, the D–A pair peak shifts to higher energy side as the excitation power increases. A weak PL peak has been observed for indirect bandgap sample, and this peak is noticed to shift to lower energy side as Al mole fraction increases. The thermal activation energies of the impurities also have been estimated by observing the temperature dependence of the PL intensity of the D–A pair peaks.