Edge-state photoconductivity mechanism of two-dimensional perovskite single crystal nanowire array
Organic-inorganic perovskite materials have excellent optoelectronic properties and are used in the preparation of high-efficiency solar cells and light-emitting diodes. Perovskites have high carrier mobility, long life and diffusion distance, and are also ideal. The photodetector material. However, the dark current of the three-dimensional perovskite has a great influence on the signal-to-noise ratio of the photodetector, and the development is limited. The photodiode detector based on the polycrystalline film can suppress the dark current, but it cannot be realized. Large photoconductive gain, device sensitivity is not ideal.
Recently, Dr. Wu Yuchen from the Institute of Physics and Chemistry of the Chinese Academy of Sciences, Jiang Lei, a member of the Chinese Academy of Sciences, and Fu Hongbing, a professor at Tianjin University, and a foreign academician of the Chinese Academy of Sciences, and Zhang Xiang, a professor at the University of California, Berkeley, collaborated to produce high-quality two-dimensional perovskites. Single crystal nanowire arrays, for the first time, found the edge-state photoconductivity of two-dimensional perovskite nanowires, and realized the world's highest sensitivity perovskite photodetectors.
The researchers controlled the crystal growth of the two-dimensional perovskite through an asymmetric infiltration interface. The electron beam diffraction, synchrotron radiation, and incident X-ray scattering revealed that the prepared nanowires were oriented in a single, conductive, low-layer perovskite and butylamine group. The ion layer is assembled to form a superlattice structure. By measuring the fluorescence and photoconductivity of nanowires with different heights, it is found that the edge of the perovskite layer can effectively split excitons, generate and conduct free carriers, thus achieving excellent photoconductivity. Based on this nanowire prepared photodetector, realized 104Responsiveness above A/W and 7×1015The detection above Jones is the most sensitive perovskite photodetector in the world, which is 2-3 orders of magnitude higher than traditional silicon photodiodes.
The relevant research results were published in "Nature-Electronics" and reported as highlight. Related research has been awarded by the Ministry of Science and Technology, the National Natural Science Foundation of China, and the Beijing Natural Science Foundation.
