Organic upconversion imager for shortwave infrared light imaging

Shortwave Infrared (SWIR) light imaging is critical in a variety of applications ranging from medical diagnosis, industrial inspection and safety monitoring, etc. due to their information-rich merits. This report presents an organic up-conversion imager for SWIR light imaging. The imager integrates an organic SWIR photodiode (OPD) and an organic light emitting diode (OLED) to convert invisible SWIR image directly into visible image without sophisticated data acquisition and processing electronics. Our imager is capable of imaging light signal with wavelength up to 1400 nm, due to the sensitivity of the novel OPD. The design guidelines for attaining highly sensitive and low voltage up-conversion imagers are revealed by studying the photo responsivity and current-voltage characteristics of the SWIR PD and OLED. The results show that the elimination of deep trap states in the SWIR PD favors the photo sensitivity and reduces the operating voltage of the up-conversion imager.