Photoluminescence property of nano-composite phases of β-FeSi₂ nanocrystals embedded in SiO₂

Abstract

We have investigated photoluminescence (PL) behaviors of nano-composite phase of -NCs embedded in SiO2 (-NCs/SiO2). The inhomogeneous spectra consisting of the A, B and C emission bands were observed. PL enhancement also was confirmed in comparison with -NCs/Si. Under high pumping rate, we observed PL spectra near room temperatures (~270 K). This fact means that oxidation of the nano-composite phase can contribute to reduction of thermal quenching, which may come from increase of band offsets around NCs..

Study on silicidation reaction of Fe nanodots with SiH4

“…[1][2][3][4][5][6][7] Recently, β-iron disilicide (FeSi 2 ) has also attracted interest as an optically active, direct-bandgap material that might be compatible with existing silicon processing technology. [8][9][10][11][12][13][14][15][16][17][18][19] Therefore, β-FeSi 2 seems to be a promising candidate for practical optical sources in Si-based optoelectronic devices. However, to improve the optical and photoluminescence (PL) properties, it is necessary to realize smooth carrier injection and confinement.…”

(Invited) Formation and Characterization of Fe-Silicide Nanodots for Optoelectronic Application

“…Among various Fe-silicides, β-FeSi 2 is the semiconductor phase with an indirect bandgap of ~0.7 eV being close to the direct bandgap value (~0.85 eV) at room temperature and shows light emission in the near-infrared region. Taking into account the tuning of optical absorption and emission properties including the improvement of luminous efficiency by using quantized structures, semiconducting β-FeSi 2 nanostructures are promising in their optoelectronic applications [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33]. In this work, we focus on low temperature formation of β-FeSi 2 nanodots (NDs) over ~10 11 cm -2 in areal density on SiO 2 and the characterization of light emission properties of β-FeSi 2 NDs.…”

Analysis of oxidation behavior in nanocrystal β-FeSi₂/Si composites by rutherford backscattering spectrometry and computation of diffusion flux

“…One of candidates is a -FeSi2/SiO2 heterojunction, which may be easy to synthesize from -FeSi2/Si heterojunctions by sample oxidation. Nakamura et al have reported synthesis of nanocrystal -FeSi2 (NC-) embedded in SiO2 by using oxidation of samples in air, and they succeeded in observation of evident photoluminescence at 250 K [3]. Moreover, Morita et al [4] have reported time dependent growth of SiO2 in oxidation of -FeSi2/Si, and they found no structural and quantitative changes of NC- by using infrared absorption (IRA) measurements, and pointed that selective oxidation took place in the sample.…”