Band Tunable Microcavity Perovskite Artificial Human Photoreceptors

Abstract

monochromatic artificial retinas. However, the monolithic realization of an artificial retina that can successfully mimic the spectral responses of rods and of all three types of cones, and can provide compatible weak-light sensitivity, short response time, and large dynamic range is very challenging. To enable a narrowband response, optical filters have been widely utilized for state-of-the-art applications. [10,11] However, optical filters are disadvantageous owing to their high costs and limited pixel densities. [12] In our previous study, we revealed that the appearances of the solar cells can be manipulated by combining microcavities with organic solar active structures. [13] However, limited spectral coverage and optical structure design flexibility hinder the implementation of the method. For instance, due to the short exciton diffusion length and poor carrier mobility, the thickness of the organic absorber layer usually must be approximately equal to or less than 100 nm; such layers only partially utilize the light that they receive. Conversely, unique optoelectronic properties such as ambipolar carrier transport, panchromatic absorption, and efficient photoresponse make organometallic halides particularly promising for use in various optoelectronic devices. [14][15][16][17][18] In this study, we demonstrated that by judiciously integrating the designed optical microcavities with vacuum-deposited perovskite photoresponse devices, high-performance filterless artificial human photoreceptors can be realized. The microcavity perovskite artificial human photoreceptors exhibit an excellent spectral match with cones sensitive to blue, green, and red colors and color-insensitive rods. Thus, the photoreceptors present a promising detectivity of 10 13 cm Hz 1/2 W −1 , a short response time of 580 ns, and a high dynamic range of up to 154 dB. Moreover, the photoreceptors can be monolithically fabricated and miniaturized owing to the fully vacuum-type fabrication process.The retina of the human eye comprises red, green, and blue cones and rods. The red, green, and blue cones are responsible for sensing the red, green, and blue colors, respectively. The rod cells are responsible for sensing the surrounding conditions when light intensity is low. Figure 1a displays the normalized response spectra of the four human photoreceptors presented in the literature. [1,2,19] These spectra reveal various features. The full width at half-maximum (FWHM) spectral widths of all of the photoreceptors are ≈100 nm for both rods and cones. The maximum response wavelengths of the blue cones, rods, green cones, and red cones are 445, 498, 540, and 565 nm, respectively.Electronic device versions of the neural functions of the human retina have high potential for use in artificial vision. This study demonstrates halide perovskite artificial human photoreceptors with specific photoresponses to red, green, and blue colors, which are consistent with human retinal photoreceiving cones and rods. In contrast to the current programmable spectral-r...

Ultrathin Single‐Crystalline 2D Perovskite Photoconductor for High‐Performance Narrowband and Wide Linear Dynamic Range Photodetection

“…[25][26][27] This prominent narrowband light absorption makes ultrathin 2D-RPPs very promising candidates for filterless narrowband photodetectors. [16,28] Besides, the distinctive single crystallinity and natural MQWs of ultrathin 2D-RPPs make it possible to effectively suppress the dark current, and consequently improve the on/off ratio of photodetectors. [23,29] Generally, 2DM photodetectors have two architectures, that is, the lateral and vertical arrangements.…”

“…Such a 15 nm wide prominent narrowband photoresponse only possesses ≈4% of the visible light spectrum ( Figure S5, Supporting Information), which makes V-PEPI-PC very potential to be applied in filterless multi-wavelength image sensors, artificial retinas, wavelength division multiplexing VLC techniques, and other applications. [16][17][18][19] A series of current-voltage (I ds -V ds ) curves of V-PEPI-PC were measured in the dark and under 517 nm light illumination with a series of illumination intensities at a given +1 V bias, as shown in Figure 2e. The I ds -V ds curve in the dark shows a dark current of 1.1 × 10 −14 A (44 pA mm −2 ), which is ultralow and near the limitation of instruments.…”

Facile Fabrication of Self‐Assembly Functionalized Polythiophene Hole Transporting Layer for High Performance Perovskite Solar Cells

“…The SA P3HT-COOH HTM device shows ultralow dark current of 7.3 × 10 −8 mA cm −2 , which is three orders of magnitude lower than the PEDOT:PSS device (4.9 × 10 −5 mA cm −2 ) at the reverse bias, because of the efficient dark current blocking and suppressed interface recombination (Figure S14, Supporting Information). It is thus an excellent candidate for ultra-sensitive low light detection, [54] as well as novel power sources for applications like indoor PSCs [55,56] and image sensor. [57] Therefore, we collected the J-V curves of PSCs at various low light intensities.…”

Prediction of Strong Transversal s(TE) Exciton–Polaritons in C60 Thin Crystalline Films

“…The theoretical approach to such systems is mostly based on the two-level or boson-boson Hamiltonian model with an arbitrary coupling constant [4,36]. Using graphene [37] or perovskite [38]-layered heterostructures, one can obtain tunable microcavity devices of high performance, which can be applied as photonic detectors or emitters [38,39], but also as platforms for studying the excitonphoton coupling.…”