Effect of phosphorus composition on the structural quality of GaInP/GaAsP short-period superlattices

Abstract

Short-period Ga0.51In0.49P/GaAsyP1−y strained superlattices were grown, by organometallic vapor phase epitaxy, with periods around 70 Å and phosphorus compositions from 0.04 to 0.31. Ground state emission as high as 1.73 eV was observed. Model solid theory predictions fit this data well, particularly at lower P compositions. Type II structures were obtained for phosphorus compositions above 0.04. The introduction of phosphorus in the low bandgap regions of these superlattices was found to significantly improve their structural and optical quality. These superlattices provide, in many applications, a viable alternative to the quaternary alloy GaInAsP, which is required for obtaining these bandgaps in Al-free systems lattice-matched to GaAs. To our knowledge this is the first report on the growth and modeling of short-period superlattices using this material system.

Near-band-gap reflectance anisotropy in orderedGa0.5In0.5P

“…18 The RD spectrum of an ordered III-V alloy generally exhibits both surface-and bulk-induced spectral features and, at times, it is difficult to separate the two effects. 15,16 Recently, however, we have developed a technique for effectively quenching the surface-induced features in ordered Ga 0.5 In 0.5 P. 19 ͑In short, this is accomplished by annealing the Ga 0.5 In 0.5 P in H 2 at a temperature of about 400°C to achieve a group-III terminated surface and then exposing this surface to N 2 or air at room temperature.͒ A typical bulk RD spectrum of ͑partially͒ ordered Ga 0.5 In 0.5 P is shown in Fig. 1.…”