SYNTHESIS AND PHOTOLUMINESCENCE OF SINGLE-CRYSTAL SILICON NITRIDE NANOWIRES VIA NITRIDING OF CRYOMILLED NANOCRYSTALLINE SILICON POWDER

摘要

The preparation of high-purity SbN4 nanowires (SNNWs) is challenging partly as a result of the poor nitriding and oxidation kinetics by traditional solid-phase synthesis methodologies [1, 2]. In this work we developed a novel synthetic methodology to fabricate dimensionaly controllable SNNWs by nitriding of cryomilled nanocrystalline silicon powder. The SNNWs consist of single-crystalline a-Si3N4, and are 30-100 nm in diameter. The formation of-Si-Si surface passivation during cryomilling process promotes the subsequent synthesis of SNNWs. The growth mechanism for SNNWs appears to be a vapor-solid reaction. Moreover, we describe doping control methods for SNNWs using doping elements selected in the order of valence electron at different blocks in the periodic table to realize control of its photoluminescence wavelengths (380-620 nm). Finally, combining first-principles simulation and optical measurements, we have established the relationship between band structures and photoluminescence properties, which reveals the photoluminescence mechanisms of SNNWs with doping elements.