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p-type conduction has been observed in unintentional carbon-doped ZnO thin films grown by metal organic chemical vapor deposition through postgrowth annealing treatment. The existence of carbon, which has been verified by secondary ion mass spectrometry and x-ray photoelectron spectroscopy, was predicted to immobilize the oxygen in the interstitial site in ZnO thin films after annealing. Using first principles calculations, the formation of carbon-oxygen cluster defect in ZnO was found to be favorable and acts as a shallow acceptor. The cryogenic photoluminescence of the p-type carbon-doped ZnO thin films shows an additional peak located at 3.3564 eV, which was attributed to the acceptor (carbon-oxygen cluster defect) bound exciton emission. [ABSTRACT FROM AUTHOR]

Single-walled carbon nanotubes (SWNTs) have been grown via chemical vapor deposition on high-κ dielectric SrTiO[sub 3]/Si substrates, and high-performance semiconducting SWNT field-effect transistors have been fabricated using the thin SrTiO[sub 3] as gate dielectric and Si as gate electrode. The transconductance per channel width is 8900 μS/μm. The high transconductance cannot be explained by the increased gate capacitance; it is proposed that the increased electric field at the nanotube–electrode interface due to the high-κ SrTiO[sub 3] decreases or eliminates the nanotube-electrode Schottky barrier. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A windowless helium lamp is employed to assist chemical vapor deposition of hydrogenated amorphous silicon from disilane feedstock gas at a film growth rate greater than 200 Å/min. Material properties in this preliminary study are comparable to the best hydrogenated amorphous silicon (a-Si:H) films produced by conventional bulk plasma CVD techniques. The amount of photoconductivity degradation under long-time illumination is more than plasma-deposited a-Si-H thin films. Photoconductivity as high as σp =4×10-4 (Ω cm)-1 has been obtained. [ABSTRACT FROM AUTHOR]

We employ a well-confined hydrogen plasma of disk shape both as a vacuum ultraviolet (VUV) lamp operating primarily at 121.5 nm and as a source of atomic hydrogen radicals. Both VUV photons and atomic hydrogen act to dissociate feedstock gases used in low-temperature (<400 °C) metalorganic chemical vapor deposition (MOCVD). Thin films have been deposited both with the confined hydrogen plasma and with an excimer laser operating at 193 nm in order to compare the two methods. Preliminary chemical and electrical properties of the films deposited via the two methods indicate the superiority of the atomic hydrogen assisted MOCVD technique. [ABSTRACT FROM AUTHOR]