Ordering dependence of carrier lifetimes and ordered states of Ga0.52In0.48P/GaAs with degree of order ⩽0.55

Photoluminescence (PL) properties and carrier lifetimes of spontaneously ordered Ga0.52In0.48P/GaAs are measured at low temperatures. Samples with values of degree of order S from 0.22 to 0.55 are used. The full width at half maximum of the PL increases from 9.36 to 30.6 meV with increasing S. The PL peak of the indirect transition is blueshifted with increasing excitation power, whereas the PL peak of the direct transition is not. The energy separation between the PL peaks for the direct and the indirect transitions becomes greater with increasing S. The carrier lifetime increases dramatically with increasing S, from 0.68 ns at S=0.22 to 13 800 ns at S=0.55 at the peak energy of the PL spectrum. The ordering dependence of these characteristics is interpreted using a simple physical model of the ordered state. Variations in the ordered state with increasing ordering are discussed.