Centre for Electronic Materials for Engineering, School of Electrical, Electronic Information Engineering, South Bank University, 103 Borough Road, London SE 10AA, UK
Abstract:
For the first time, thin film devices of charge transfer adducts of tetrathiafulvalene (TTF) have been fabricated. A luminance of 5 cd m−2 has been achieved for a device structure ITO/poly(aniline)/TTF(NO3)0.55/Al whose EL spectrum has a broad peak at 645 nm. The devices were fabricated by spin coating from solutions of the adducts. A luminous efficiency of 5×10−4 lm W−1 has been obtained for these devices which is comparable to that of ITO/poly(aniline)/Alq3/Al (5.2×10−4 lm W−1) under same fabrication conditions. The single layer, mixed layer and double layer devices fabricated in this study fit the space charge limited model. Devices fabricated from the adduct TTF–Alq3] emit white light (40 cd m−2) with a luminous efficiency of 6.6×10−4 lm W−1. The colour of light emitted appears to depend on the effective oxidation state of TTF in the adducts.