Easily Processable Cu2O/Si Self-Powered Photodetector Array for Image Sensing Applications

The fabrication of a conventional photodetector array (PDA) involves complex photolithography technology for pixel isolation. An easy process is essential for the mass production of PDAs. This study explores a facile method of fabricating a PDA that comprises 4 × 4 p-Cu2O/n-Si photodiode cells. A solution-processed p-type Cu2O film is patterned by removing the UV-shielded portion by immersing it in water. The efficient separation of electron/hole pairs at the Cu2O/Si interface enables self-powered operation with a responsivity of 0.3 A/W and a fast response speed (∼10 ms). The PDA has relatively good uniformity and negligible variation between pixels. It records simple characters with a satisfactory resolution and exhibits negligible degradation over 3 months. The combination of self-powering characteristics, high reliability, and easy processability indicates that this PDA can be used for image sensing applications.