Spatially resolved near-field spectroscopy on localized GaInAsP/InP double heterostructures

We present investigations of band-gap variations on selective grown GaxIn1-xAsyP1-y multiple quantum wells (MQW, Q1.05) using near-field optical microscopy. The MQW is excited with the near-field probe and the luminescence is collected through the same tip. By this mode, we are able to detect variation of the band gap with a lateral resolution of about 550 nm at a luminescence wavelength of 1115 nm. We show a spatial band-gap modulation near the (0-11) facet of the selective grown structures, which we suggest, is a result of a variation of the material composition, Furthermore, together with the simultaneously recorded topography, we are able to allocate a recombination path at a Center wavelength of lambda=1115 nm to the intersection of the (01-1) and (11-1) vertical side facets, which are formed by interfacet diffusion during surface selective growth of the GaxIn1-xAsyP1-y MQW. (C) 1998 American Institute of Physics. [S0021-8979(98)06102-7].