Fig. 12: Artificial retinas and vision systems based on perovskite semiconductors.

a Device and schematic of the human vision system containing: (i) synapse and (iii) photoreceptor, as well as the corresponding (ii) & (iv) device mimicking (i) and (iii). A cross-sectional SEM showing the device configuration. Reproduced with permission from ref. ⁵⁰⁴. b Cross-sectional SEM micrograph showing FAPbI₃ nanowire crystal in the aluminum oxide membrane micro mold through a vapor deposition. Band diagram and working principle of the nanowire device. Reproduced with permission from ref. ²⁷. c Structural configuration of an ultrathin photodetector arrays. Reproduced with permission from ref. ⁵⁰⁷. d Cross-sectional SEM micrograph and device configuration of a band tunable microcavity integrated on a perovskite photoreceptor. Reproduced with permission from ref. ⁵⁰⁸. e Schematic of the optical synapse device made of 2D perovskites. Reproduced with permission from ref. ⁵¹¹. f Illustration of a retina-inspired narrowband perovskite photodetector (PD) system for panchromatic imaging. It includes schematic designs of two configurations: typical parallel and stacking layouts of the panchromatic imaging sensor. Inspired by the neural network architecture of the human eye, a three-layer neuromorphic algorithm is depicted for signal processing and image reconstruction. Finally, a photo of a prototype perovskite NB PD array developed in this work is shown, demonstrating the practical implementation of the design. Reproduced with permission from ref. ²⁴.