24.48%-efficiency Industrial TOPCon Solar Cell with Low-temperature Al 2 O 3 /MoO x Hole-selective Contacts

Abstract

Thanks to the excellent passivation, high conductivity, low parasitic absorption and simple process, the wide-bandgap doping-free carrier selective contacts have been attracting much attention. In this work, the wide-bandgap high work function of Al O /MoO stacks were prepared using the low-temperature atomic layer deposition and thermal evaporation technique, respectively, and the interfacial evolution and the elements distribution were examined using high-resolution transmission electron microscopy coupled with energy-dispersive spectroscopy. The passivation and conductivity of the Al O /MoO stacks were systematical investigated by varying their thicknesses. The high effective minority carriers lifetime of 513 μs and the low series resistance of 0.24 mΩ are realized on the 7nm-Al O /5nm-MoO and 7nm-Al O /3nm-MoO stacks, respectively. Benefiting from the excellent surface passivation and conductivity, the industrial size (182×185.3 mm ) n-TOPCon solar cell with a total area front 7nm-Al O /3nm-MoO stacks demonstrates a champion power conversion efficiency (PCE) of 24.48%, as well as a short-circuit current density of 41.06 mA cm , an open-circuit voltage of 721 mV, and a fill factor of 82.66%. This work provides an effective way to enable the PCE over 26.0% and lower the process temperature for TOPCon solar cells with doping-free carrier selective contacts.