Doped poly-silicon (poly-Si) passivating contacts have emerged as a key technology for next-generation silicon solar cells due to their excellent performance and compatibility with existing passivated emitter and rear cell (PERC) technology. However, the current PERC architecture with rear-side electron-selective (n⁺) poly-Si contacts is approaching its practical limit of ~26% efficiency in mass production. To fully realize the potential of doped poly-Si passivating contacts, both electron-selective (n⁺) and hole-selective (p⁺) poly-Si contacts are needed. While studies of both n⁺ and p⁺ poly-Si contacts began around the same time, significant performance differences have emerged, with phosphorus-doped poly-Si contacts consistently outperforming boron-doped counterparts due to lower recombination current density (J₀) values. This discrepancy is attributed to inadequate optimization of p⁺ poly-Si contacts and fundamental limitations related to boron doping, such as boron segregation into interfacial oxide layers, which compromises interfacial oxide integrity and reduces chemical passivation effectiveness. This review critically examines the progress of p⁺ poly-Si contacts characterized by cell efficiency and J₀ values, explores existing challenges, identifies potential solutions, and discusses potential solar cell architectures to enhance efficiency by incorporating p⁺ poly-Si contacts. The current solar cell architecture based on a rear-side n⁺ poly-Si contact (TOPCon) is also approaching its practical limit of ~26% in mass production. A detailed loss analysis of state-of-the-art doped poly-Si solar cells suggested that recombination loss on the front contacts is one of the main sources of efficiency loss. Therefore, the full potential of poly-Si-based passivating contact solar cells could only be realized by incorporating p⁺ poly-Si contacts to replace the traditional boron diffused contacts on the front surface. Other reports also concluded that high-efficiency solar cells with doped poly-Si passivating contacts will require both n⁺ and p⁺ poly-Si contacts. This work projected that fully passivating contact solar cells could achieve efficiencies greater than 27.5%, surpassing the limitation of current n-type TOPCon solar cells (26%). While studies of both p⁺ and n⁺ poly-Si contacts started around the same time, there has been a notable discrepancy in their performance. A comparison between the present status of p⁺ and n⁺ poly-Si contacts is shown in Fig. 2(a), based on reported efficiencies of both-sides-contacted solar cells. Numerous research groups and PV manufacturers have consistently demonstrated high-efficiency (>25%) solar cells employing n⁺ poly-Si contacts. The efficiency of solar cells utilizing n⁺ poly-Si contacts has shown rapid improvement, with PV manufacturers such as Jinko, Longi, Trina, Jollywood, and DAS solar unveiling impressive efficiency improvements within a short timeframe. HoweverDoped poly-silicon (poly-Si) passivating contacts have emerged as a key technology for next-generation silicon solar cells due to their excellent performance and compatibility with existing passivated emitter and rear cell (PERC) technology. However, the current PERC architecture with rear-side electron-selective (n⁺) poly-Si contacts is approaching its practical limit of ~26% efficiency in mass production. To fully realize the potential of doped poly-Si passivating contacts, both electron-selective (n⁺) and hole-selective (p⁺) poly-Si contacts are needed. While studies of both n⁺ and p⁺ poly-Si contacts began around the same time, significant performance differences have emerged, with phosphorus-doped poly-Si contacts consistently outperforming boron-doped counterparts due to lower recombination current density (J₀) values. This discrepancy is attributed to inadequate optimization of p⁺ poly-Si contacts and fundamental limitations related to boron doping, such as boron segregation into interfacial oxide layers, which compromises interfacial oxide integrity and reduces chemical passivation effectiveness. This review critically examines the progress of p⁺ poly-Si contacts characterized by cell efficiency and J₀ values, explores existing challenges, identifies potential solutions, and discusses potential solar cell architectures to enhance efficiency by incorporating p⁺ poly-Si contacts. The current solar cell architecture based on a rear-side n⁺ poly-Si contact (TOPCon) is also approaching its practical limit of ~26% in mass production. A detailed loss analysis of state-of-the-art doped poly-Si solar cells suggested that recombination loss on the front contacts is one of the main sources of efficiency loss. Therefore, the full potential of poly-Si-based passivating contact solar cells could only be realized by incorporating p⁺ poly-Si contacts to replace the traditional boron diffused contacts on the front surface. Other reports also concluded that high-efficiency solar cells with doped poly-Si passivating contacts will require both n⁺ and p⁺ poly-Si contacts. This work projected that fully passivating contact solar cells could achieve efficiencies greater than 27.5%, surpassing the limitation of current n-type TOPCon solar cells (26%). While studies of both p⁺ and n⁺ poly-Si contacts started around the same time, there has been a notable discrepancy in their performance. A comparison between the present status of p⁺ and n⁺ poly-Si contacts is shown in Fig. 2(a), based on reported efficiencies of both-sides-contacted solar cells. Numerous research groups and PV manufacturers have consistently demonstrated high-efficiency (>25%) solar cells employing n⁺ poly-Si contacts. The efficiency of solar cells utilizing n⁺ poly-Si contacts has shown rapid improvement, with PV manufacturers such as Jinko, Longi, Trina, Jollywood, and DAS solar unveiling impressive efficiency improvements within a short timeframe. However