Thermal growth, luminescence and whispering gallery resonance modes of indium oxide microrods and microcrystals

Indium oxide microcrystals with shapes of truncated cubes and pyramids as well as microrods with square, triangular or hexagonal cross-sections are grown by a catalyst free evaporation deposition method. Size and shape control of the crystals as a function of the treatment parameters is discussed. Their luminescence properties are investigated and some features in the cathodoluminescence images are suggested to be related to the possible formation of a core dislocation. The waveguiding behaviour of the rods as well as whispering gallery resonances with improved Q-factor are demonstrated for hexagonal and square cross-section rods. The effect of tapering of the rods on the resonance wavelength is also studied and fitted to a theoretical model.