Photoluminescence and X-ray diffraction studies of MBE-grown compressively strained InGaAs and InGaAlAs quantum wells for 1.55 μm laser diode applications

Abstract

Compressively strained InGaAs and InGaAlAs multiple quantum wells were grown on InP by molecular beam epitaxy and their material qualities were investigated by double-crystal X-ray diffraction (DCXRD) and photoluminescence (PL). From the satellite peaks in a DCXRD scan, precise layer structures were determined. By comparing PL spectra of strained quantum wells having different well thicknesses, 75 Å thick quantum wells were found to be more suitable for laser diode applications than thinner wells. To achieve the required lasing wavelength of 1.55 μm with 75 Å wide strained quantum wells, quaternary InGaAlAs quantum wells were studied. It was also found that quaternary InGaAlAs strained quantum wells are less prone to strain relation than ternary InGaAs.