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 2O
3/MoO x 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 2O 3/MoO
x 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
2O 3/5nm-MoO x and
7nm-Al 2O 3/3nm-MoO x
stacks, respectively. Benefiting from the excellent surface passivation
and conductivity, the industrial size (182×185.3 mm 2)
n-TOPCon solar cell with a total area front 7nm-Al 2O
3/3nm-MoO x stacks demonstrates a
champion power conversion efficiency (PCE) of 24.48%, as well as a
short-circuit current density of 41.06 mA cm −2, 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.