Published online by Cambridge University Press: 01 February 2011
GaNyAs1−x−yBix alloys were grown by molecular beam epitaxy (MBE) using solid Ga, Bi, and As sources and nitrogen radicals generated from N2 in rf plasma. To achieve Bi incorporation into the epilayer, As flux was adjusted in a limited range on the brink of As shortage on the growing surface. GaNyAs1−x−yBix alloys lattice-matched to GaAs substrates with different photoluminescence (PL) peak energies were obtained. The GaNyAs1−x−yBix alloy lattice-matched to GaAs turned out to have the structure of Ga(N0.34Bi0.66)zAs1−z. The PL spectra showed that the PL peak energy of GaNyAs1−x−yBix alloy decreased with increasing Bi and N contents with redshift coefficients of ∼62 meV/%Bi and ∼130 meV/%N, respectively, at room temperature. The temperature dependence of the PL peak energy for GaNyAs1−x−yBix in the temperature range of 150∼300 K is much smaller than that of InGaAsP. The temperature coefficients of GaNyAs1−x−yBix bandgaps were governed by the GaBi molar fraction and decrease with increasing GaBi molar fraction.