Characterization of a-B5C:H prepared by PECVD of orthocarborane: Results of preliminary FTIR and nuclear reaction analysis studies

Annealing effects on the optical properties of semiconducting boron carbide

“…A characteristic B-H bond stretching mode was reported to occur around 2560 cm −1 . 6,24,25 Analysis of the B 5 C thin film IRSE data presented here reveals strong variations of absorption resonances associated with boron-hydrogen and boron-carbon bond properties and development of an icosahedral signature accompanied by film thickness reduction on annealing.…”

Photofragmentation of the closo-Carboranes Part II: VUV Assisted Dehydrogenation in the closo-Carboranes and Semiconducting B10C2Hx Films

“…The hydrogen content suggests that decomposition of the closo-carboranes, to form the C 2 B 10 H x boron carbide semiconductor, does not result in complete fragmentation of the icosahedral cage. Despite the determined 40 at% H concentration in carborane saturated plasma grown films, 13 some dehydrogenation must occur off the icosahedral carborane cage during semiconducting boron carbide film growth as otherwise the resulting semiconducting film would exhibit a much higher band gap 4,5,14-16 and would not form stable semiconductor devices to high temperatures, as is observed, 3 although densification is observed with some boron carbides, 17 presumably due to hydrogen loss. Knowledge of the molecular decomposition and fragmentation of boron-containing cage molecules are of central importance to our understanding of the relationships between the PECVD process and resulting materials properties.…”

“…[5][6][7][8][9][10]12 The method of choice, at present, for making semiconducting boron carbide thin films is to use closo-1,2-dicarbadodecaborane (ortho-carborane), and its isomers, as a source gas(es) for radical-induced polymerization via plasma-enhanced chemical vapor deposition (PECVD). The resulting boron carbides, of approximate stoichiometry "C 2 B 10 H x " (where x represents up to 40 at% fraction of hydrogen 13 ), exhibit a range of electronic properties but are all semiconductors. The hydrogen content suggests that decomposition of the closo-carboranes, to form the C 2 B 10 H x boron carbide semiconductor, does not result in complete fragmentation of the icosahedral cage.…”

Insights into the local electronic structure of semiconducting boron carbides in the vicinity of transition metal dopants

“…Semiconducting boron carbides are based on the packing of icosahedra [32], and may contain a significant amount of hydrogen [33], so defects are expected in this material. Successful boron carbide homojunctions have, nonetheless, been fabricated by plasma enhanced chemical vapor deposition (PECVD) of carboranes, with Ni [34,35], Co [32,36], Fe [37] and Mn [32] doping.…”