HgCdTe APD passivation layer, preparation method and application thereof

The invention discloses a tellurium-cadmium-mercury APD passivation layer, a preparation method and application thereof, and the method comprises the steps: carrying out the wet chemical corrosion of a liquid-phase epitaxial tellurium-cadmium-mercury material based on a tellurium-zinc-cadmium substrate through employing a bromine methanol solution and a lactic acid aqueous solution, and then depositing and growing a cadmium telluride passivation layer on the surface, and performing closed tube saturated mercury pressure thermal annealing to form a high-component transition layer on the surface of the tellurium-cadmium-mercury epitaxial material, depositing and growing a cadmium telluride film on the surface of the tellurium-cadmium-mercury chip after closed tube annealing, and performing vacuum thermal treatment to obtain the p-type tellurium-cadmium-mercury material with required concentration. The high-component diffusion layer formed on the tellurium-cadmium-mercury surface through tube sealing annealing c