Evidence for strain-induced lateral carrier confinement in InGaAs quantum wells by low-temperature near-field spectroscopy

A strain-induced lateral variation of the band edges of a 10-nm-thick In0.1 6Ga0.84As quantum well embedded in GaAs is achieved by patterning of a 100- nm-thick compressively strained In0.52Ga0.48P stressor layer. The strain mo dulation results in a splitting of the 10 K far-field photoluminescence (PL ) spectra into two emission peaks. Spectrally resolved two-dimensional near -field PL images establish a clear spatial and spectral separation of the t wo far-field PL peaks, indicating a lateral carrier confinement with a conf inement energy of about 10 meV. Finite-element calculations of the strain d istribution are used to determine the lateral band-edge shifts and are well in agreement with the experimental findings. (C) 2001 American Institute o f Physics.