Abstract
High-quality bulk layers of (AbGa1-J o.5 In o.5 P (x = 0 to 1.0) and (AbGa1-J o.5 In o.5 P/Gao.5Ino.5P (a;=0.4, 0.7 and 1.0) quantum wells (QWs) have been grown on 2°- and 15°-off-(l00) GaAs substrates by means of low-pressure metalorganic vapor phase epitaxy at a high growth rate of 9 A/s. The high-resolution transmission electron microscopic (TEM) image indicates the interfacial abruptness to be on the order of one monolayer. Photoluminescence (PL) results indicate an increase in peak energy and a decrease in full width at half-maximum (FWHM) for samples grown on 15°-off substrates, due to the suppression of sublattice ordering. For QWs with a direct barrier, an intense and distinct PL peak can be clearly observed for well thickness as thin as 9 A. However, no emission is observed for the 9 A well in the Al o.5 In o.5 P/Ga o.5 In o.5 P QWs, due to the indirect transition from the X-valley in AllnP to the heavy hole valence band of GalnP. For the first time, (Al o.7 Ga o.3 ) o.5 ln o.5 P/Ga o.5 ln o.5 P multiple quantum wells (MQWs) with well widths of 9 A have been obtained. The 20 K PL peak energy corresponds to a wavelength of 545 nm, the shortest ever reported for (AbGa1-J o.5 In o.5 P/Ga o.5 In o.5 P MQWs. © 1993 The Japan Society of Applied Physics.