High efficiency polymer photodiodes

Organic polymer photodiodes have been fabricated using different device des igns, and by the use of blends between derivatives of poly(thiophene) and p oly(phenylene vinylene), a broad wavelength response is accomplished. For s ingle layer devices, an external quantum yield of 4.5% is achieved under sh ort-circuit conditions, increasing to 28% at 2V negative bias. Even better results are found for double layer devices, having a spectral response cove ring the range from 350 nm to 750 nm, and exhibiting 28% external quantum y ield at short circuit and reaching almost 60% at -2V bias.