EETimes: Researchers from Siemens Corporate Technology (CT) have developed a cost-effective production process for organic large-area photo diodes: Instead of the usual method of casting or doctor blading, they succeeded in spraying the material.
The Siemens researchers claim their spraying method generates active semiconductor of a rather good quality. They say that the diodes feature very low dark current and also a very high efficiency of 75%. In addition, the lifetime can be expected at six years, and the speed is high enough to use the diodes in computer tomography applications. The image lag, another relevant parameter for these applications, is significantly better than with available photo detectors made of amorphous silicon.
The prototype introduced by the Siemens researchers features 256 x 256 pixels, but since the process scales well, it is said to be possible to produce diode arrays with more than 1000 x 1000 pixels.
Meanwhile, Fujifilm researchers present their organic sensor paper on Technical Group on Information Sensing Technologies (IST) meeting on July 24, 2009 in Japan. Their paper is titled:
"CMOS Image Sensor with a Thin Overlaid Panchromatic Organic Photoconductive Layer as the Best Candidate for Sensors with Reduced Pixel Size."