Thick junction broadband organic photodiodes

Inorganic semiconductor-based broadband photodetectors are ubiquitous in imaging technologies such as digital cameras and photometers. Herein a broadband organic photodiode (OPD) that has performance metrics comparable or superior to inorganic photodiodes over the same spectral range is reported. The photodiode with an active layer comprised of a poly[N-9-heptadecanyl-2,7-carbazole-alt-5,5-(4,7-di-2-thienyl-2,1,3-benzothiadiazole)]:[6,6]-phenyl-C-71-butyric acid methyl ester bulk heterojunction blend had a dark current < 1 nA/cm(2), specific detectivity of approximate to 10(13) Jones, reverse bias -3 dB frequency response of 100 kHz to 1 MHz, and state-of-the-art Linear Dynamic Range for organic photodiodes of nine orders of magnitude (180 dB). The key to these performance metrics was the use of a thick junction (700nm), which flattened the spectral response, reduced the dark current and decreased performance variations. The strategy also provides a route to large area defect free monolithic structures for low noise integrated photo-sensing, position determination, or contact, non-focal imaging.