Preliminary results on the first hot wire deposited a-SiC:H based thin film light emitting p-i-n diode having the structure glass/TCO(SnO2:F)/p-a-SiC:H/i-SiC:H/n-a-SiC:H/Al are reported. The paper discusses the results of our attempts to optimize, the p-, i- and the n-layers for the desired electrical and optical properties. The optimized p-layers have a bandgap E-g similar to 2 eV and conductivity a little lower than 10(-5) (Omega cm)(-1). On the other hand, the optimized n-type a-SiC:H show a conductivity of similar to10(-4) (Omega cm)(-1) with bandgap 2.06 eV The highest bandgap of the intrinsic layer is approximately 3.4 eV and shows room temperature photoluminescence peak at approximately 2.21 eV. Thin film p-i-n diodes having i-layers with E-g from 2.7 to 3.4 eV show white light emission at room temperature under forward bias of >5 V. However, the 50-nm thick devices show appreciable reverse leakage current and a low emission intensity, which we attribute to the contamination across the p-i interface since these devices are made in a single chamber with the same filament. (C) 2003 Elsevier Science B.V. All rights reserved.