Nature Electronics: progress in the field of high performance 2D perovskite single crystal nanowire array photodetectors

Organic-inorganic perovskite materials have excellent photoelectric properties and are used to prepare high efficiency solar cells and light-emitting diodes Perovskite is a kind of ideal photodetector material with high carrier mobility, long lifetime and diffusion distance However, the three-dimensional perovskite dark current has a great influence on the signal-to-noise ratio of photodetectors, and its development is limited Although the photodiode detector based on polycrystalline film can suppress dark current, it can not achieve large photoconductive gain and the sensitivity of the device is not ideal Recently, Dr Wu Yuchen of Institute of physical and chemical technology of Chinese Academy of Sciences, Jiang Lei, academician of Chinese Academy of Sciences, Professor Fu Hongbing of Tianjin University, foreign academician of Chinese Academy of Sciences and Professor Zhang Xiang of University of California, Berkeley, USA High quality arrays of two-dimensional perovskite single crystal nanowires have been fabricated The edge state photoconductivity effect of two-dimensional perovskite nanowires has been found for the first time, and the perovskite photodetector with the highest sensitivity in the world has been realized The researchers controlled the crystal growth of two-dimensional perovskite through asymmetric wetting interface Through electron diffraction and synchrotron radiation grazing incidence X-ray scattering, it is found that the nanowires have a single orientation, and the conductive few layers of perovskite and butylamine ions are assembled layer by layer to form a superlattice structure By measuring the fluorescence and Photoconductivity of nanowires with different heights, it is found that the edge of the calcium titanium deposit can effectively split the excitons, generate and conduct free carriers, thus achieving excellent photoconductivity The photodetectors based on the nanowires achieve a response of more than 104a / W and a detection of more than 7 × 1015 Jones They are the most sensitive perovskite photodetectors in the world at present, and their performance is 2-3 orders of magnitude higher than the traditional silicon photodiodes The results were published in nature Electronics (DOI: 10.1038 / s41928-018-0101-5) and reported as highlight Relevant research has been supported by key special projects of the Ministry of science and technology, key projects of National Natural Science Foundation and general projects of Beijing Natural Science Foundation.