On TCAD Simulation of Tunnel Oxide Passivated Contact Rear Emitter (TOPCoRE) Solar Cell Featuring Localized MoO x as a Hole‐Selective Contact

The tunnel oxide passivated contact rear emitter (TOPCoRE) solar cell is a promising alternative to TOPCon technology, effectively reducing lateral current and recombination losses in silicon (Si) solar cells. This study employs the Silvaco ATLAS to evaluate the photovoltaic performance of an advanced TOPCoRE configuration, which features a hole‐selective layer of molybdenum oxide (MoO x ) and a rear junction stack of SiO 2 / n + ‐polySi (TOPCon). Key design parameters assessed include the MoO x work function, thicknesses of MoO x and SiO 2 , electrons' effective mass ( m c ), total interface states at the c‐Si/SiO 2 interface (D it ), and surface recombination velocity. The findings reveal that quasi‐Fermi level splitting influences recombination characteristics. An optimal MoO x work function of 6.9 eV with a thickness of 7 nm enhances the Schottky barrier against minority carriers. A thicker SiO 2 layer improves passivation but reduces tunneling, affecting fill factor ( FF ). Both m c and D it impact quantum tunneling across SiO 2 . The proposed device achieved V OC of 731 mV, improving to 747 mV with localized MoO x contact, indicating enhanced passivation due to an increased contact area with moderately‐doped Si and SiN x /Al 2 O 3 stack. It also recorded J SC of 42.48 mA/cm 2 , FF of 81%, and conversion efficiency exceeding 25.5%, highlighting the TOPCoRE's potential for optimizing Si solar cell performance.