Organometallic synthesis of gallium-arsenide crystallites, exhibiting quantum confinement

The optical spectra of semiconductor crystallites whose dimension is comparable to the bulk exciton diameter show quantum confinement effects.'"To date, experimental studies of nanometer-size crystallites have been restricted to 11-VI and I-VI1 semiconductors, while 111-V semiconductors, including one of the most important direct band gap semiconductors, GaAs, have not yet been studied in this form, because of the numerous difficulties encountered in their preparation.Compared to the I-VI1 and 11-VI semiconductors, the 111-Vs have a greater degree of covalent bonding, a less ionic lattice, and larger exciton diameters (the exciton diameter in GaAs is 190 8, compared to 60 8 for CdS).