Title of article :
Effects of Hydrogen and Helium Dilution on the Optical Band Gap and Photoluminescence of DC PECVD Hydrogenated Amorphous Carbon Films
Author/Authors :
Awang, Rozidawati National University of Malaysia (UKM) - School of Applied Physics, Malaysia , Rahman, Saadah A. university of malaya - Solid State Research Laboratory Physics Department, Malaysia
From page :
265
To page :
269
Abstract :
A series of hydrogenated amorphous carbon (a-C:H) thin films were deposited using home-built direct-current (DC) plasma enhanced chemical vapour deposition (PECVD) system. In this present study, the a-C:H thin films were deposited using pure methane (CH4) gas diluted either with hydrogen (H) or helium (He). The effects of hydrogen and helium dilution on the photoluminescence (PL) properties and optical band gap (E04) were studied. The dependence of PL properties and optical energy gap on the film thickness has also been investigated. The characterization techniques used were optical transmission and photoluminescence spectroscopies. The sp2 cluster sizes were determined from Raman spectra are in the range of 5 to 7 nm. Hydrogen and helium dilution of methane strongly influences the PL efficiency of the a-C:H films. The PL efficiency are enhanced with increase in film thickness for a-C:H films prepared both from H and He diluted CH4. The optical energy gap of these films decreases with increase in H or He dilution and film thickness
Keywords :
hydrogenated amorphous carbon , hydrogen and helium dilution , PL , optical band gap
Record number :
2554619
Link To Document :
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