High-performance solution-processed flexible Cu2O photodetector via UV-irradiation

Solution processing of metal oxide semiconductors (MOS) is widely used for electronic and optoelectronic applications. However, the high-temperature annealing process that is required for device-quality films is incompatible with a flexible substrate because plastics can be thermally damaged. This study fabricates a p-type Cu2O flexible photodetector (PD) with a metal-semiconductor-metal structure on a polyethylene terephthalate (PET) substrate by irradiating a preheated precursor film with ultraviolet (UV) light. High-quality Cu2O crystals are formed on PET substrates by the charge transfer transition that is excited by the UV-irradiation at room temperature. An extremely high photo-to-dark current ratio (PDCR) of 1590 is achieved for a solution-processed Cu2O flexible PD. This flexible PD exhibits a relatively fast photoresponse (-0.2 s) and folds reproducibly after repeated bending for 500 cycles. This process does not require conventional high-temperature thermal annealing and is applicable to other solution-processed MOS, particularly those that are used for flexible electronic applications.

Automated summary

This study successfully fabricates a p-type Cu2O flexible photodetector on a PET substrate by UV irradiation, resulting in high-quality Cu2O crystals. The photodetector achieves an extremely high photo-to-dark current ratio, relatively fast photoresponse, and reproducible folding after repeated bending. This solution processing method eliminates the need for high-temperature annealing and is applicable to other solution-processed MOS for flexible electronic applications.