STRUCTURAL AND OPTICAL CHARACTERIZATION OF STRAINED AND STRAIN-COMPENSATED INGAASP INP QUANTUM-WELL LASER STRUCTURES/

InGaAsP/InP strained and strain-compensated multi-quantum wells grown by low pressure metalorganic chemical vapor deposition for fabricating 1.3 mu m lasers were characterized by double crystal X-ray diffractio n, transmission electron microscopy, atomic force microscopy, cathodol uminescence, and photoluminescence. The quantum wells were compressive ly strained at 1.14% or 2.55%. Strain-compensated structures were obta ined by using appropriately tensile-strained barriers so that the net strain of the multi-quantum well region is approximately zero. It is o bserved that the sample which had a strain of 2.55% in the wells and w hich was strain-compensated showed the poorest structural and optical quality. Also, the sample which had a strain of 2.55% and uncompensate d showed an inhomogeneous layer growth compared to the sample which ha d a strain of 1.14%. The results also showed that a quantum well strai n of 1.14% can be compensated without affecting the structural and opt ical quality of the layers. (C) 1998 Elsevier Science B.V. All rights reserved.