氢化硅烷化的硅纳米晶体的光致发光.docVIP

 Photoluminescence from hydrosilylated silicon nanocrystals# 5 10  Abstract: The surface of hydrogen-passivated silicon nanocrystals (Si NCs) is modified via a styrene-based hydrosilylation scheme. It is found that the peak position of the photoluminescence (PL) from hydrosilylated Si NCs is hardly affected by hydrosilylation time. However, the quantum yield (QY) of the PL from hydosilylated Si NCs decreases with the increase of hydrosilylation time. During the storage of hydrosilylated Si NCs in air the PL from hydrosilylated Si NCs blueshifts, while the PL QY for hydosilylated Si NCs initially increases and then decreases. The underlying mechanisms for all the optical behavior of hydrosilylated Si NCs are discussed. Key words: Silicon nanocrystals; Surface; Hydrosilylation; Luminescence; Quantum yield 15 0 Introduction Freestanding silicon nanocrystals (Si NCs) are of great importance due to easy access to their surface and the flexibility of incorporation in device structures [1, 2]. In most of the practical uses of freestanding Si NCs, surface modification should be firstly carried out to render the dispersibility 20 25 30 35 40 of freestanding Si NCs in desired medium. As a leading surface-modification scheme, hydrosilylation has been routinely used for freestanding Si NCs [3-6]. The photochemical hydrosilylation of Si NCs has been investigated by Gupta et al. [7], Li et al. [8] and Kelly et al. [9]. By monitoring the in situ changes of photoluminescence (PL) from Si NCs, Kelly et al. were able to elucidate the mechanisms for photochemical hydrosilylation [9]. The thermal hydrosilylation of Si NCs has been performed by Jurbergs et al. [4]. However, the effect of thermal hydrosilylation time on the PL from Si NCs has not been carefully studied. In addition, the detailed evolution of PL from thermally hydosilylated Si NCs during extended exposure to air is also elusive. In this work we carry out thermal hydrosilylation for Si NCs by the use of styrene. T