10.1021/acsami.7b05146.s001
Yoon Ho Choi
Yoon Ho
Choi
Hyun Bin Kim
Hyun Bin
Kim
In Seok Yang
In Seok
Yang
Sang Do Sung
Sang Do
Sung
Young Sik Choi
Young Sik
Choi
Jeongho Kim
Jeongho
Kim
Wan In Lee
Wan In
Lee
Silicotungstate, a Potential
Electron Transporting Layer for Low-Temperature Perovskite Solar Cells
American Chemical Society
2017
Li 4 SiW 12 O 40
CH 3 NH 3 PbI 3 PSC device
electron
OC
TiO 2 layer
FF
PCE
uniform Li-ST films
photovoltaic conversion efficiency
FTO
ETL
Li-ST layer
Low-Temperature Perovskite Solar Cells
60 nm-thick Li-ST layer
coating
CH 3 NH 3 PbI 3
Li-ST buffer layer
2017-07-12 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Silicotungstate_a_Potential_Electron_Transporting_Layer_for_Low-Temperature_Perovskite_Solar_Cells/5226340
Thin
films of a heteropolytungstate, lithium silicotungstate (Li<sub>4</sub>SiW<sub>12</sub>O<sub>40</sub>, termed Li-ST), prepared by a solution
process at low temperature, were successfully applied as electron
transporting layer (ETL) of planar-type perovskite solar cells (PSCs).
Dense and uniform Li-ST films were prepared on FTO glass by depositing
a thin Li-ST buffer layer, followed by coating of a main Li-ST layer.
The film thickness was controlled by varying the number of coating
cycles, consisting of spin-coating and thermal treatment at 150 °C.
In particular, by employing 60 nm-thick Li-ST layer obtained by two
cycles of coating, the fabricated CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> PSC device demonstrates the photovoltaic conversion efficiency
(PCE) of 14.26% with <i>J</i><sub>SC</sub> of 22.16 mA cm<sup>–2</sup>, <i>V</i><sub>OC</sub> of 0.993 mV and
FF of 64.81%. The obtained PCE is significantly higher than that of
the PSC employing a TiO<sub>2</sub> layer processed at the same temperature
(PCE = 12.27%). Spectroscopic analyses by time-resolved photoluminescence
and pulsed light-induced transient measurement of photocurrent indicate
that the Li-ST layer collects electrons from CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> more efficiently and also exhibits longer
electron lifetime than the TiO<sub>2</sub> layer thermally treated
at 150 °C. Thus, Li-ST is considered to be a promising ETL material
that can be applied for the fabrication of flexible PSC devices.