The improvement on blue light emission from hydrogenated amorphous silicon carbide films prepared from an organic source

A series of hydrogenated amorphous silicon carbide (a-Si(1-x)C(x):H) films (0 < x less than or equal to 1) was grown by using an organic source, xylene (C(8)H(10)), instead of methane (CH(4)) in a conventional plasma enhanced chemical vapor deposition system. The optical band gap of these samples was altered over a wide range by changing the gas ratio of C(8)H(10) to SiH(4); the maximum ratio was 3.5 eV. Photoluminescence (PL) measurements were carried out at room temperature by using a Xe lamp as an excitation light for samples deposited at different conditions. Contrary to earlier reports, we found that the PL peak is blueshifted with increasing optical band gap and the PL intensity increased. (C) 1998 Elsevier Science B.V. All rights reserved.