Subwavelength pixelated CMOS color sensors based on anti-Hermitian metasurface

Abstract

The demand for essential pixel components with ever-decreasing size and enhanced performance is central to current optoelectronic applications, including imaging, sensing, photovoltaics and communications. The size of the pixels, however, are severely limited by the fundamental constraints of lightwave diffraction. Current development using transmissive filters and planar absorbing layers can shrink the pixel size, yet there are two major issues, optical and electrical crosstalk, that need to be addressed when the pixel dimension approaches wavelength scale. All these fundamental constraints preclude the continual reduction of pixel dimensions and enhanced performance. Here we demonstrate subwavelength scale color pixels in a CMOS compatible platform based on anti-Hermitian metasurfaces. In stark contrast to conventional pixels, spectral filtering is achieved through structural color rather than transmissive filters leading to simultaneously high color purity and quantum efficiency. As a result, this subwavelength anti-Hermitian metasurface sensor, over 28,000 pixels, is able to sort three colors over a 100 nm bandwidth in the visible regime, independently of the polarization of normally-incident light. Furthermore, the quantum yield approaches that of commercial silicon photodiodes, with a responsivity exceeding 0.25 A/W for each channel. Our demonstration opens a new door to sub-wavelength pixelated CMOS sensors and promises future high-performance optoelectronic systems.

Recent Advances in Reconfigurable Metasurfaces: Principle and Applications

“…If the metal patterns of metasurfaces are etched on the silicon wafer by chemical vapor deposition or electroplating and connected with the field effect transistor manufactured by the CMOS technique, the structures of the metasurfaces can be changed and various functions can be realized by controlling the on–off states of the FETs. Another advantage of the CMOS technique is that even the circuits fabricated by the outdated 90 nm or 65 nm technique is still relatively small compared with the micron size in the terahertz band, so it is convenient to design multi-bit metasurface unit cells with this technique [ 258 , 259 ].…”

Metasurface Photodetectors

“…Zhang et al, further demonstrated sub-wavelength scale color pixels in a CMOS compatible platform based on Anti-Hermitian metasurfaces (Figure 7p) [60]. The AH Silicon metasurfaces, with two-dimensional arrays of three differently sized nanocylinders, are coupled with a shallow PIN junction for efficient carrier transport and electrical readout.…”

High-Sensitivity Sensing in All-Dielectric Metasurface Driven by Quasi-Bound States in the Continuum

“…It may further realize the fully chip-integrated optical sensing and detecting functions and be readily integrated with numerous functionalities [ 10 ]. The silicon material device technology is established, affordable, and compatible with the CMOS process [ 38 , 39 ]. Thus, researchers’ interest has been drawn to silicon-based high refractive index sensor chips.…”