Flexible Stacked Perovskite Photodetectors for High-Efficiency Multicolor Fluorescence Detection

A flexible,multicolor detector based on stacked perovskite layerswith graded band gaps was presented. Different perovskite layers generatea series of photocurrents corresponding to light intensities at differentwavelengths. Experimentally, the flexible detector demonstrated acceptablelong-term stability and temperature stability in the bending state.To demonstrate the advantages of the flexible multicolor detectorin biological applications, a tubular-shaped multicolor fluorescencedetector that embraces the sample cell was constructed. As a result,the detection limits of three kinds of CdTe quantum dots (QDs) withcentral wavelengths of 545, 625, and 730 nm were 0.52, 0.85, and 0.43nM, respectively, which was significantly improved by more than 10times compared to those of planar detectors. Additionally, the detectorwas able to detect three kinds of QDs simultaneously in a mixed solution,and the relative deviation was smaller than 10% compared to the presetconcentration. These results demonstrate that the flexible stackedperovskite detector and the tubular-shaped detection configurationhold promise for the simultaneous fluorescent detection of multiplebiomolecules.