Semiconductor photonic dots: Visible wavelength-sized optical resonators

Here we describe a strategy toward constructing semiconductor photonic dots in the ultraviolet to blue region. An array of ZnS dots was grown on a GaAs substrate with a selective growth method. The ZnS dots have a pyramidal structure with the base plane of 800 nm square and the height of 300 nm. The {034} crystallographic planes form the sidewalls of the pyramids. Therefore, the size of the pyramidal dots is uniquely determined by the mask patterning. The optical reflection spectra showed clear resonance peaks which are reasonably assigned by the calculation of the resonance modes. Each resonance showed the Q values on the order of 160-300, a reasonable value to observe the modification of the total spontaneous emission rate in this kind of photonic dots. (C) 1999 American Institute of Physics. [S0003-6951(99)03614-1].