Introducing the tunneling oxide passivated contact （TOPCon） structure into the back contact solar cells structure， a tunneling oxide passivated contact back contact （TBC） solar cell was prepared， which can effectively suppress the recombination of electrons and holes， and improve the photoelectric conversion efficiency. This article focuses on the preparation process of the emitter of p-type TBC solar cells， and deeply studies the preparation process and passivation performance of n-type tunneling oxide passivation contact structures （n-TOPCon） on p-type silicon wafers. Through experiments， the influence of oxidation time on the thickness of the oxide layer during the growth process of the tunneling oxide layer was studied， and the effect of different thicknesses of tunneling oxide layers on the passivation of the emitter n-TOPCon structure was investigated. The experimental results show that at an oxidation temperature of 600 ℃ and an oxidation time of 1 200 s， the tunneling oxide layer thickness reaches 1.52 nm， and the optimal passivation performance could be obtained. At this time， the hidden implied open circuit voltage reaches 733 mV， corresponding to J₀ of 4.41 fA/cm². Afterwards， the doping distribution curve and passivation performance of n-TOPCon emitter under different phosphorus diffusion temperatures and phosphorus source flow rates were studied. When the diffusion temperature reaches 870 ℃， the implied open circuit voltage of n-TOPCon can be increased to 736 mV. As the diffusion temperature increases， the implied open circuit voltage of the emitter n-TOPCon structure begins to decrease. Finally， the relationship between the passivation performance of n-TOPCon structure and N₂-POCl₃ flow rate was studied under the same diffusion temperature. Through experiments， it is found that with the increase of diffusion N₂-POCl₃ flow rate， the passivation performance of n-TOPCon structure first improve and then decrease. According to the test results， when the N₂-POCl₃ flow rate is 3 000 sccm， the hidden open circuit voltage of n-TOPCon structure can be increased to 740 mV.