For the study, we
prepared a low grain boundary three-dimensional
CH
3
NH
3
PbI
3
crystal (3D-MAPbI
3
) on TiO
2
nanoarrays by inhibition of ammonium
iodide and discussed the formation mechanism of the crystal. Based
on the 3D-MAPbI
3
crystal, solar cells showed modified performance
with a power conversion efficiency (PCE) of up to 19.3%, which increases
by 36.8% in contrast to the counterparts. We studied the internal
photocurrent conversion process. The highest external quantum efficiency
is up to 92%, and the electron injection efficiency is remarkably
facilitated where the injection time decreases by 37.8% compared to
the control group. In addition, based on 3D-MAPbI
3
, solar
cells showed excellent air stability, which possesses 78.3% of the
initial PCE, even though they were exposed to air for 30 days. Our
results demonstrate a promising approach for the fabrication of perovskite
solar cells with high efficiency and stability.