Visible-blind Near-infrared Photodetectors Based On Perovskite Light Filtering Layer

The visible blind near infrared photodetector is a photosensitive device with narrow spectral absorption in the near infrared region.The aim is to solve the problem of the influence of visible light on the accuracy of traditional near-infrared detectors under bright environment.It has wide application in scientific research,monitoring and so on.In this paper,visible and blind near infrared photodetectors are fabricated by combining organic near-infrared photosensitive diode and perovskite filter layer.In this paper,a photodiode based on PbPc/C₆₀ heterojunction is selected as the near-infrared optical detection part.However,such devices exhibit obvious light response in the visible near infrared region.Because the perovskite material has high optical absorption in the visible region,the perovskite filter layer can effectively absorb the energy of the visible part of the incident light,and the optical response of the whole device is limited to the near infrared region.First,the optical response of perovskite thin film at different channel length and incident wavelength is studied.The optical response of the perovskite thin film reaches 10³ mA/W,showing more than 300%external quantum efficiency,and the light response in the visible region is far greater than that of the near infrared region.Next,the light response capability of the device in reverse mode is studied and analyzed.At the same time,the photosensitive diode based on PbPc/C₆₀ heterojunction is prepared and optimized.The optical responsivity of the device without perovskite filter layer is 100²00 mA/W,and the optical responsiveness of the device after the perovskite filter layer is reduced to 10 mA/W in the visible light region.The near-infrared region is only reduced to 80mA/W,and the realization of visible blind near infrared detection is realized.In this paper,by combining the characteristics of PbPc/C₆₀ heterojunction and perovskite in photosensitive region,the visible blind near infrared photodetector is prepared,and excellent experimental results have been obtained.Through the experiment and analysis and optimization,the direction is pointed out for further research.