A Solution-Processed Hole-Transporting Layer Based on p-Type CuCrO2 for Organic Photodetector and Image Sensor

In this study, p-type delafossite CuCrO 2 nanomaterials are synthesized via a one-step hydrothermal reaction. An organic photodiode (OPD) with an inverted stack is fabricated by utilizing such CuCrO 2 as the hole-transporting layer. The single OPD device shows the dark current density of 6.48 × 10 −8 A cm −2 , and an external quantum efficiency of 16.2% at a 525 nm illumination, and a −5 V bias. Its responsivity and detectivity are 68.5 mA W− 1 and 4.75 × 10 11 cm Hz 1/2 W −1 , respectively. A large-area, flat-panel image sensor is also realized similarly by applying the materials and structure onto a thin-film transistor backplane. The active area and pitch of flat-panel sensor are 75.0 mm × 81.0 mm and 150 µm, respectively and its resolution is 510 × 470. The performance of the organic image sensor is evaluated. The results indicate the materials and device have potential applications for the flat-panel detector.