Organic Imager on Readout Backplane Based on TFTs With Cross-Linkable Dielectrics

We report on the fabrication of imagers based on organic semiconductors both in the photodiode layer and in the readout backplane. The photodiode is based on evaporated ultrathin ( 60 , sensitive in the wavelength range between 300 and 650 nm. The readout circuit is a switch matrix fabricated with a solution processed semiconductor (XPRD30B01) and two solution processed, cross-linkable dielectrics (XDRD30B01). The readout TFTs (140/5- \(\mu \) m channel width/length, respectively) have leakage current lower than 1 pA with the ON-current higher than 0.1 \(\mu \) A. The \(32\times 32\) pixel imagers with pixel pitch down to 200 \(\mu \) m are demonstrated with mean dark signal of a few \(\mu \) A/cm \(^{2}\) and linear photoresponse up to the incident power of 100 \(\mu \) W. These results show feasibility of fabricating readout circuits with TFTs based on cross-linkable dielectrics. This enables reduction of two patterning steps (opening of the gate dielectric and of the encapsulation layer) to just photolithography, leading to simplification of the backplane manufacturing process.