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The main goal of solar cell technology is to attain high efficiency, long durability, mass-production, cost-effectiveness, and made with eco-friendly materials. Among the various crystalline silicon solar cell technologies, Tunneling Oxide Passivated Contact (TOPCon) solar cell has its unique style in terms of the structure and carrier transport manner, which predominately decreases the metal contact recombination and gives 1-D carrier transport. A very high efficiency of 26% for TOPCon solar cells has been achieved with the industrial screen print technology and obtained high cell parameter values of Vocand fill factor as 732.3 mV and 84.3% respectively. The tunnel oxide thickness (maintaining < 2 nm) in the TOPCon has its prior impact on the efficiency and electrical parameters of the cell. To obtain the preferable thickness of the tunnel oxide layer various deposition techniques have been reported in the literature. SiOxis the most widely used tunnel oxide material for TOPCon solar cells to date. In this review, different deposition methods that were used for the SiOxtunnel oxide layer such as chemical oxidation, ozone oxidation, thermal oxidation, and plasma-enhanced chemical vapor deposition (PECVD) are elaborated. Moreover, the effect of the deposition conditions on the cell parameters in different techniques are also discussed briefly. Furthermore, the development of TOPCon solar cells and the latest reports that were used different tunnel oxide materials in finding an alternative to SiOxtunnel oxide is discussed.

This study focuses on the enhanced passivation and gettering of boron‐doped p‐type solar grade silicon wafers by incorporating carrier‐selective and passivating tunnel oxide contact (TOPCon). A symmetrical stack of aluminum oxide (Al2O3)/p‐doped n‐type polysilicon (n‐poly‐Si)/ ultrathin silicon oxide (SiOx) in conjunction with long cycles of forming gas annealing is used for enhancing the silicon wafer quality with a novel approach. Multilayer of n‐poly‐Si/SiOxon p‐type crystalline silicon wafer exhibits an implied open‐circuit voltage (iVoc) of 726 mV, effective carrier lifetime (τeff) of 857 μs, and a low recombination current density (Jo) of 1.9 fA cm−2when subjected to a postdeposition annealing (PDA) of phosphorus‐doped hydrogenated amorphous silicon (n‐a‐Si:H) at 820 °C. To boost passivation and gettering quality, 10 nm‐thick Al2O3layers on both sides of n‐poly‐Si/SiOxsamples are added. This leads to improved τeff(962 μs), reduced Jo(1.1 fA cm−2), and higher iVoc(728 mV). Herein, a thinner 50 nm n‐poly‐Si layer for improved properties is applied. The experiments show improved passivation and gettering. A Quokka‐3 simulation examines the potential of high‐efficiency p‐type TOPCon cells. A novel solar‐grade p‐type wafer quality enhancement approach is introduced, amalgamated with Quokka‐3 results, which could be a milestone in high‐efficiency p‐type TOPCon solar cell production. Novel rear emitter p‐type passivating tunnel oxide contact (TOPCon) solar cells with n‐polysilicon passivated contacts are studied. Excellent passivation quality is achieved with iVocof 728 and J0of 1.1 fA cm−2. A proposed roadmap toward the 24.19% of the rear emitter p‐type TOPCon solar cell is studied.