jz500003v_si_001.pdf (444.13 kB)
Solid-State Mesostructured Perovskite CH3NH3PbI3 Solar Cells: Charge Transport, Recombination, and Diffusion Length
journal contribution
posted on 2015-12-17, 00:27 authored by Yixin Zhao, Alexandre M. Nardes, Kai ZhuWe
report on the effect of TiO2 film thickness on charge
transport and recombination in solid-state mesostructured perovskite
CH3NH3PbI3 (via one-step coating)
solar cells using spiro-MeOTAD as the hole conductor. Intensity-modulated
photocurrent/photovoltage spectroscopies show that the transport and
recombination properties of solid-state mesostructured perovskite
solar cells are similar to those of solid-state dye-sensitized solar
cells. Charge transport in perovskite cells is dominated by electron
conduction within the mesoporous TiO2 network rather than
from the perovskite layer. Although no significant film-thickness
dependence is found for transport and recombination, the efficiency
of perovskite cells increases with TiO2 film thickness
from 240 nm to about 650–850 nm owing primarily to the enhanced
light harvesting. Further increasing film thickness reduces cell efficiency
associated with decreased fill factor or photocurrent density. The
electron diffusion length in mesostructured perovskite cells is longer
than 1 μm for over four orders of magnitude of light intensity.