Image sensors combining an organic photoconductor with a-Si:H matrix addressing

Organic semiconductor thin films offer new opportunities for large area electronics. In addition to having good electrical properties in thin film transistors and sensors, these materials can often be deposited by simple techniques such as dip-coating or jet-printing. We have fabricated two-dimensional imagers with organic light sensors, and report good imaging properties. The 512×512 element array has pixel size of 100 μm, and is addressed using amorphous silicon thin film transistors. The design allows a continuous layer of the organic sensor material without the need for pixel-level patterning, and so can take advantage of simple coating techniques. The sensors are bi-layers comprising a thin generator layer and a thicker hole transport layer. Three different sensors have been studied with generator layers comprising evaporated benzimidazole perylene (BZP) and dispersions of hydroxygallium phthalocyanine (HOGaPc) and titanyl phthalocyanine (TiOPc).