Abstract:
The design of electron transport layers (ETLs) with good optoelectronic properties is one of
the keys to the improvement of the power conversion efficiencies (PCEs) and stability of perovskite
solar cells (PSCs). Titanium dioxide (TiO2), one of the most widely used ETL in PSCs, is characterized
by low electrical conductivity that increases the series resistance of PSCs, thus limiting their PCEs. In
this work, we incorporated tin oxide (SnO2) into titanium dioxide (TiO2) and studied the evolution
of its microstructural and optoelectronic properties with SnO2 loading. The thin films were then
integrated as ETLs in a regular planar Formamidinium (FA)-rich mixed lead halide PSCs so as
to assess the overall effect of SnO2 incorporation on their charge transport and Photovoltaic (PV)
characteristics. Analysis of the fabricated PSCs devices revealed that the best performing devices;
based on the ETL modified with 0.2 proportion of SnO2; had an average PCE of 17.35 1.39 %, which
was about 7.16% higher than those with pristine TiO2 as ETL. The improvement in the PCE of the
PSC devices with 0.2 SnO2 content in the ETL was attributed to the improved electron extraction and
transport ability as revealed by the Time Resolved Photoluminescence (TRPL) and Electrochemical
Impedance Spectroscopy (EIS) studies.
