Infrared absorption of amorphous boron films containing carbon and hydrogen

Abstract

Optical transmission spectra of vacuum deposited amorphous boron films are obtained, at room temperature, in the near infrared over the range 700 to 4000 cm-' (14 to 2.5 pm). Absorption bands are observed and identified as due to hydrogen and carbon which are deliberately introduced into the films during deposition. The concentrations of hydrogen and carbon present in each film are determined by secondary-ion mass-spectrometry analysis. Intensities of I R bands attributed to hydrogen and carbon are found to correlate with hydrogen and carbon content, respectively.On a Btudie dans l'infrarouge proche entre 700 it 4000 cm-I (14 it 2,5 pm), le spectre optique de transmission B temperature ambiente, pour couches minces du bore amorphe obtenu sous vide. Les bandes d'absorption dues B I'hydroghe et au carbone introduit expressbment dans les Bchantillons au cours de la deposition ont 6th observees et identifiees. La concentration de I'hydroghne et du carbone dans chaque Bchantillon a bt6 determine par spectrombtrie de masse des ions secondaires. On a trouve une correlation entre les intensites des bandes infrarouges attribuees a l'hydrog h e et au carbone et les concentrations respective5 de I'hydrogAne et du carbone.

Optical properties and chemical reactivity of hydrogenated amorphous boron thin films

“…In the as-deposited films (a) and (b), no absorption feature can be detected above the 2560 cm -1 band and the feature at 2350 cm-1 is an artefact due to the CO2 background. By comparison with the diborane absorption [11] and previous studies of a-B:H alloys thin films [6,8], the sharp 2560 and broad 2050 cm-1 bands are readily attributed to the terminal B-H bond stretching and the B-H-B bridge bond absorption, respectively. However the spectra of the as-deposited material show no clear evidence of the 1108 cm -1 band previously attributed to the B-H bending mode [-5].…”

“…The introduction of hydrogen atoms in the boron network has been achieved either by diborane B2H 6 pyrolysis [5] and plasma-assisted chemical vapour deposition [2,4,6,7], or by electron beam evaporation of boron in a residual hydrogen atmosphere [8]. Very large amounts of incorporated hydrogen atoms have been revealed by infrared absorption [1,6,8], 15N nuclear reaction [1,5] and hydrogen thermal effusion I-6], up to 30% and 45%, respectively, at deposition temperatures of 270 and 30 ~ [6"].…”

Sputter deposition of high resistivity boron carbide

“…The second absorption band rises from the B-H terminal linkage at 2560 cm −1 [23]. In contrast to this, the major absorption band in the sputter deposited fi lm occurs at 1100 cm −1 which correlates strongly with the amount of carbon present in the fi lm [23] and to various B-C vibrations [23][24][25]. The second absorption band at 1550 cm −1 arises from the stretching of the B-H ′ bridge bond.…”

Dibromocarbene Functionalization of Boron Nitride Nanosheets: Toward Band Gap Manipulation and Nanocomposite Applications

“…Finally, UV-Vis spectroscopy was employed to assess the modification of the intrinsic optical energy transitions as a result of the covalent functionalization. the E 1u B-C stretching mode, [42][43][44] while the strong shoulder band at 1078 cm -1 is indicative of the C-N bond. 42 Concomitant formation of both B-C and B-N bonds indicates the formation of a BCN heterocyclic structure as the carbene group binds to both B and N atoms in the BNNS lattice to satisfy its unpaired electron pair.…”