OPTICAL-PROPERTIES OF GAAS CONFINED IN THE PORES OF MCM-41

We report on GaAs/MCM-41 heterostructures synthesized by deposition of GaAs into the channels of MCM-41 using metalloorganic chemical vapor deposition. MCM-41 consists of an ordered array of silica tubules comp rising pores with uniform and controllable diameter in the nanometer r ange. The GaAs/MCM-41 heterostructures show blue-shifted absorption an d broad visible photoluminescence even at room temperature. The photol uminescence maximum depends on the MCM-41 pore diameter supporting for mation of size-quantized semiconductor crystallites whose growth is re stricted by the diameter of the pores of MCM-41. The shift in the phot oluminescence spectra as a function of the excitation wavelength sugge sts a broad size distribution of the GaAs particles crystallized on th e outside of MCM-41 and a relatively narrow size distribution of the G aAs particles inside the channels of MCM-41.