Neuromorphic vision sensors have been extremely beneficial in developing energy-efficient intelligent systems for robotics and privacy-preserving security applications.There is a dire need for devices to mimic the retina's photoreceptors that encode the light illumination into a sequence of spikes to develop such sensors.Herein,we develop a hybrid perovskite-based flexible photoreceptor whose capacitance changes proportionally to the light intensity mimicking the retina's rod cells,paving the way for developing an efficient artificial retina network.The proposed device constitutes a hybrid nanocomposite of perovskites (methyl-ammonium lead bromide) and the ferroelectric terpolymer (polyvinylidene fluoride trifluoroethylene-chlorofluoroethylene).A metal-insulator-metal type capacitor with the prepared composite exhibits the unique and photosensitive capacitive behavior at various light intensities in the visible light spectrum.The proposed photoreceptor mimics the spectral sensitivity curve of human photopic vision.The hybrid nanocomposite is stable in ambient air for 129 weeks,with no observable degradation of the composite due to the encapsulation of hybrid perovskites in the hydrophobic polymer.The functionality of the proposed photoreceptor to recognize handwritten digits (MNIST) dataset using an unsupervised trained spiking neural network with 72.05％ recognition accuracy is demonstrated.This demonstration proves the potential of the proposed sensor for neuromorphic vision applications.

Mani Teja Vijjapu;Mohammed E.Fouda;Agamyrat Agambayev;Chun Hong Kang;Chun-Ho Lin;Boon S.Ooi;Jr-Hau He;Ahmed M.Eltawil;Khaled N.Salama

Sensors lab,Advanced Membranes and Porous Materials Center,Computer,Electrical and Mathematical Science and Engineering Division,King Abdullah University of Science and Technology (KAUST),Thuwal 23955-6900,Kingdom of Saudi Arabia;Communication and Computing Systems Lab,Computer,Electrical and Mathematical Science and Engineering Division,King Abdullah University of Science and Technology (KAUST),Thuwal 23955-6900,Kingdom of Saudi Arabia;Department of Electrical Engineering and Computer Science,University of California-Irvine,Irvine,CA 92612,USA;Department of Electrical,Computer and Energy Engineering,Arizona State University,Tempe,AZ,USA;Computer,Electrical and Mathematical Science and Engineering Division,King Abdullah University of Science and Technology (KAUST),Thuwal 23955-6900,Kingdom of Saudi Arabia;Department of Materials Science and Engineering,City University of Hong Kong,Hong Kong SAR,China

光：科学与应用（英文版）

[1]Mani Teja Vijjapu;Mohammed E.Fouda;Agamyrat Agambayev;Chun Hong Kang;Chun-Ho Lin;Boon S.Ooi;Jr-Hau He;Ahmed M.Eltawil;Khaled N.Salama-.A flexible capacitive photoreceptor for the biomimetic retina)[J].光：科学与应用（英文版）,2022(01):38-49

terpolymer,trifluoroethylene,chlorofluoroethylene

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