COMPOSITION AND TEMPERATURE-DEPENDENCE OF THE DIRECT-BAND-GAP OF S-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-0.0232) USING CONTACTLESS ELECTROREFLECTANCE

The composition and temperature dependence (20K<T < 380K) of the direc t gap, E-0, of a series of GaAs1-xNx/GaAs (0 less than or equal to x l ess than or equal to 0.0232) samples has been measured using contactle ss electroreflectance. Our results for the composition dependence off, are different in relation to a recent experiment [W.G. Bi and C.W Tu, Appl. Phys. Lett. 70, 1608 (1997)]. In contrast to previously reporte d results, we find that the temperature dependence of the direct gap i s in fact dependent on N composition and that the parameters which des cribe the temperature dependence of the band gap lie between those of GaAs and GaN.