Evidence of quantum size effect in nanocrystalline silicon by optical absorption

2019-11-24 17:08:42

Si absorption size gap phonon

责任者: Matsumoto, T.;Suzuki, J.-i.;Ohnuma, M.;Kanemitsu, Y.;Masumoto, Y. 单位: Japan Sci. & Technol. Corp., Tsukuba, Japan 来源出处: Physical Review B (Condensed Matter and Materials Physics)(Phys. Rev, B, Condens, Matter Mater. Phys. (USA)),2001/05/15,63(19):195322-1 摘要: The optical absorption spectrum in nanocrystalline silicon (n-Si) was determined from both light transmittance and reflectance measurements. We observed that n-Si has a phonon structure in the optical absorption spectrum. This structure originates from momentum-conserving TO phonon absorption and emission, and provides direct evidence that n-Si is an indirect-band-gap semiconductor with quantum size effects. By using small-angle X-ray scattering to measure the nanocrystal size distribution, we found that the band-gap widening varies as (1/L)1.6 with decreasing nanocrystal diameter L 关键词: elemental semiconductors;energy gap;light absorption;nanostructured materials;phonon spectra;silicon;size effect;visible spectra;X-ray scattering;quantum size effect;nanocrystalline Si;nc-Si;optical absorption;light transmittance;light reflectance;phonon structure;momentum-conserving TO phonon absorption/emission;indirect-band-gap semiconductor;small-angle X-ray scattering;nanocrystal size distribution;SAXS;band-gap widening;Si