Picosecond time-resolved photoluminescence microscopy of short period impurity free vacancy disordered AlGaAs gratings

Abstract

Impurity free vacancy disordering (IFVD) is a post-growth means of cation intermixing in binary semiconductor heterostructures that can be used to produce lateral modulation of the constituent material without the need for deep etching and growth procedures, and thus has enormous potential for the integration of such features as optical waveguides and quantum confined heterostructures into planar devices. IFVD is performed by coating the semiconductor surface with SiO/sub 2/ or with SiO/sub 2/:P prior to an anneal stage, resulting in distinct intermixing-enhanced and intermixing-suppressed regions, respectively due to a difference in the associated rates of cation out-diffusion. We have performed time-resolved photoluminescence microscopy on GaAs/AlGaAs multiple quantum wells that have been processed into one dimensional gratings by spatially selective IFVD. Results indicate that a complex relationship exists between the absolute stripe widths, the stripe width ratio, and the period, in determining the optical properties of the grating.