Preparation method of PIN type infrared photoelectric detector with ultrahigh external quantum efficiency

The invention discloses a preparation method of a PIN type infrared photoelectric detector with ultrahigh external quantum efficiency, and the method comprises the steps: regulating the proportion of SnI2 and PbI2 in a perovskite precursor solution, and introducing a stepped temperature difference method to achieve the lead-tin distribution of lead-tin alloy perovskite in different element proportions; therefore, band gap gradual change of the perovskite material is controlled to realize a multi-exciton effect between band gaps, and finally the photoelectric detector obtains ultrahigh external quantum efficiency. Comprising the following steps: S1, carrying out ultraviolet ozone treatment on a conductive substrate, preparing a PEDOT hole transport layer by adopting a spin coating method, and carrying out annealing treatment; s2, spin-coating the perovskite precursor solution on the perovskite layer obtained in the step S1 by adopting a stepped temperature difference method, and performing annealing treatment