Size- and doping-dependent time-resolved photoluminescence of doped Si nanocrystals

Abstract

Time-resolved photoluminescence (PL) has been studied for B- and Sb-doped Si nanocrystals (NCs) fabricated by ion beam sputtering and annealing. For B-doped Si NCs, the PL intensity as well as the PL lifetime (τPL) increases as NC size (d) varies from 1.5 to 2.6 nm, similar to the case for undoped Si NCs, but with further increase of d, they decrease, possibly resulting from the increase of optically less active NCs with the increase of NCs containing more dopants. The PL intensity and τPL monotonically decrease with increasing doping concentration (nD), irrespective of doping element. Si NCs show smaller τPL in B doping than in Sb doping over the full range of nD. The sharp decrease in PL intensity, accompanied by the gradual decrease in τPL for the higher nD of Sb, may be attributed to Auger recombination due to the presence of Sb inside Si NCs. The higher PL quench rate by Sb compared to B could be attributed to better ionization of Sb dopants in Si NCs.

Tight-Binding Calculations of the Optical Response of Optimally P-Doped Si Nanocrystals: A Model for Localized Surface Plasmon Resonance

“…Similar to other semiconductor NCs [11,12], the doping of Si NCs is challenging, in particular given selfpurification (dopant segregation to the NC surface) could occur [13]. In spite of these difficulties, the introduction of P and/or B impurities into Si NCs has been demonstrated [14][15][16][17][18][19][20]. There are even a few reports [21][22][23][24] showing high doping levels (>1 at %) compatible with plasmonic effects.…”

Morphology of Salivary and Lacrimal Glands

“…The PRPs are thought to serve as a defense mechanism against dietary tannins by forming precipitates, which reduce harmful effects of tannins [60]. Statherin adsorbed onto hydroxyapatite can promote adherence of a few oral bacteria, such as P. gingivalis and Actinomyces viscosus [61].…”

Electronic structure of Si nanocrystals codoped with boron and phosphorus

“…New directions of research have greatly benefited from the synthesis of colloidal Si NCs characterized by high structural quality, narrow size distribution, and PL quantum yields sometimes above 60% [3][4][5]. Other interesting developments came from the synthesis of Si NCs doped with donor (P,As) or acceptor (B) impurities [6][7][8][9][10][11][12][13][14][15]. The incorporation of impurities inside the NCs has been clearly demonstrated, in particular using atom probe tomography (APT) analysis [14][15][16][17][18], but the role of these impurities and their electrical doping efficiency remain sources of important debates [19,20].…”