Flexible, polymer-based light sensor arrays on active-matrix backplanes fabricated by digital inkjet printing

• MRS Spring Meeting 2007

As macro-electronics applications scale towards larger areas, array fabrication will become increasingly complex with conventional methods of device processing, such that photolithography and vacuum deposition will reach a practical limit. Low-temperature integration of inorganic and polymeric materials onto flexible platforms would enable low-cost, large-area image sensors by reducing materials and fabrication costs. We have developed prototypes of flexible light sensor arrays fabricated using polymeric sensor materials on polyethylene naphthalate substrates. The photo-sensitive materials were comprised of layered organic semiconductors, in which a transparent, hole-transporting layer of tetraphenyldiamine is spin-casted on top of a low bandgap polymer that dictates the spectral response of the sensor. The sensor layer has shown quantum efficiency of ~1% at 488 nm and a dark current of 1.1 pA/mm2. This layer is integrated onto a flexible a-Si:H active matrix backplane fabricated using digital inkjet printing to create a 180x180 pixel array with 75 dpi resolution. Sensor properties such as sensitivity, spectral response, and spatial resolution are determined and compared to those of conventional amorphous silicon photodiodes.

citation

Ng, T. ; Wong, W. S. ; Lujan, R. A. ; Apte, R. B. ; Chabinyc, M. ; Limb, S. ; Street, R. A. Flexible, polymer-based light sensor arrays on active-matrix backplanes fabricated by digital inkjet printing. Materials Research Society Spring Meeting; 2007 April 9-13; San Francisco; CA; USA.