A team led by Maksym V. Kovalenko and Sergii Yakunin of ETH Zurich in Switzerland published a research paper titled "Vertically Stacked Monolithic Perovskite Color Photodetectors" in the journal Nature. Sergey Tsarev is the first author, and Maksym V. Kovalenko and Sergii Yakunin are co-corresponding authors.
Key Highlight: This paper proposes an innovative color image sensor architecture: a lead halide perovskite thin-film photodetector array using a multilayer single-crystal stack. External quantum efficiencies for the red, green, and blue channels reach 50%, 47%, and 53%, respectively, with a color accuracy of 3.8% (ΔE<sub>Lab</sub>), outperforming existing filter arrays and Foveon-type sensors.
Modern color image sensors face bottlenecks in improving sensitivity and image quality, primarily due to inherent limitations in light utilization efficiency. These limitations are primarily due to the use of passive optical filters, which absorb and scatter significant amounts of light, reducing light capture efficiency.
In contrast, vertically stacked architectures like the Foveon structure attempt to overcome the filter issue through active optical filtering, but their poor color selectivity still hinders accurate color imaging and results in suboptimal performance.
In light of this, Sergii Yakunin, Maksym V. Kovalenko, and others at ETH Zurich and the Swiss Federal Institute for Materials Science and Technology proposed an innovative color image sensor architecture: a lead halide perovskite thin-film photodetector array stacked in a multilayer single-crystal stack. Leveraging the perovskite's tunable bandgap, it achieves selective absorption of the red, green, and blue visible light spectrum, eliminating the need for traditional filters. Experimental results demonstrate external quantum efficiencies of 50%, 47%, and 53% for the red, green, and blue channels, respectively, with a color accuracy of 3.8% (ΔE<sub>Lab</sub>), surpassing existing filter arrays and Foveon-type sensors. This image sensor design improves light utilization efficiency in color sensors, paving the way for the next generation of highly sensitive, artifact-free, and color-fidelity imaging.
Figure 1. Schematic diagram, architecture, and EQE spectra of different image sensor architectures.
Figure 2 Stacked detector architecture and its performance
Figure 3. Color accuracy of stacked detectors
Figure 4. Imaging using a monolithic stacked detector array in a cross-array arrangement.
This research successfully constructed a full-color, monolithic, vertically stacked perovskite photodetector architecture, offering an attractive alternative to the currently widely used color filter arrays (CFAs) and Foveon sensors.
Paper link: https://doi.org/10.1038/s41586-025-09062-3