Effect of subsurface boron on photoluminescence from silicon nanocrystals

• Published in: Surface science Vol. 605; no. 7; pp. 799 - 801
• Main Authors: Salivati, Navneethakrishnan, Shuall, Nimrod, McCrate, Joseph M., Ekerdt, John G.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.04.2011; Elsevier
• Subjects: Augers; Boron; Chemical bonds; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Desorption; Deuterium; Exact sciences and technology; Nanocrystals; Passivation; Photoluminescence; Physics; Quenching; Silicon; Silicon nanocrystals; Temperature programmed desorption; Silicon nanocrystals; Boron; Temperature programmed desorption; Photoluminescence; Passivation; TDS; Inorganic compounds; Desorption; Hot wire; Radicals; Film growth; Quenching; CVD; Dangling bonds; Silicon oxides; Transition elements; Tungsten; Silicon; Ultrahigh vacuum; Nanocrystal
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/j.susc.2011.01.022

Silicon (Si) nanocrystals (NCs) less than 5 nm in diameter are grown on SiO 2 surfaces using hot wire chemical vapor deposition in an ultrahigh vacuum chamber and the dangling bonds are passivated using atomic deuterium. The passivated NCs are subsequently exposed to BD x radicals formed by dissociating deuterated diborane (B 2D 6) over a hot tungsten filament and photoluminescence quenching is observed. Temperature programmed desorption spectra reveal the presence of additional D 2 desorption peaks beyond those found for surfaces that have only been passivated by atomic deuterium. The additional peaks appear at lower temperatures and this can be attributed to deuterium desorption from surface Si atoms bonded to subsurface boron atoms. The subsurface boron likely enhances nonradiative Auger recombination leading to photoluminescence quenching. ► The effect of boron doping Si nanocrystals on deuterium desorption is reported. ► A hot wire filament is used to dissociated D 2 to D and B 2D 6 to BD x. ► Deuterium passivates Si dangling bonds and unreconstructs the surface dimer bonds. ► Boron backbonds with the silicon surface atoms and the next layer of silicon. ► The boron enhances nonradiative Auger recombination and quenches photoluminescence.