Highly Compact TiO2 Films by Spray Pyrolysis and Application in Perovskite Solar Cells

Transparent and pinhole free hole‐blocking layers such as TiO2 grown at low temperatures and by scalable processes are necessary to reduce production costs and thus enabling commercialization of perovskite solar cells. Here, the authors compare the transport properties of TiO2 compact layers grown b...

Full description

Saved in:
Bibliographic Details
Published in:Advanced engineering materials 2019-04, Vol.21 (4), p.n/a
Main Authors: Möllmann, Alexander, Gedamu, Dawit, Vivo, Paola, Frohnhoven, Robert, Stadler, Daniel, Fischer, Thomas, Ka, Ibrahima, Steinhorst, Maximilian, Nechache, Riad, Rosei, Federico, Cloutier, Sylvain G., Kirchartz, Thomas, Mathur, Sanjay
Format: Article
Language:English
Subjects:
low temperature
perovskite solar cells
photovoltaics
spray pyrolysis
TiO2
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Transparent and pinhole free hole‐blocking layers such as TiO2 grown at low temperatures and by scalable processes are necessary to reduce production costs and thus enabling commercialization of perovskite solar cells. Here, the authors compare the transport properties of TiO2 compact layers grown by spray pyrolysis from commonly used titanium diisopropoxide bisacetylacetonate ([Ti(OPri)2(acac)2]) precursor to films grown by spray pyrolysis of TiCl4. Spray pyrolysis provides insights into the interdependence of precursor chemistry and electron transport properties of TiO2 films and their influence on the performance of the perovskite solar cells. X‐ray diffraction and X‐ray photoelectron spectroscopy data confirm the chemical and structural composition of the obtained films. Thin film deposition at lower temperature (150 °C) are conducted using TiCl4 to evaluate the influence of crystal growth and topography by scanning electron microscopy and atomic force microscopy as well as thickness (profilometry) and transmittance (UV/Vis spectroscopy) on the power conversion efficiency of perovskite solar cells. TiO2 compact layers grown from TiCl4 enhance the power conversion efficiency by acting as superior electron transfer medium and by reducing hysteresis behavior, when compared to films grown using titanium diisopropoxide bisacetylacetonate. UV/Vis spectroscopy and external quantum efficiency studies reveal the correlation of transmittance on the power conversion efficiency. Compact TiO2 thin films are reproducibly obtained by spray pyrolysis of TiCl4 at relatively low temperatures (150–450 °C). Integration of spray‐deposited TiO2 compact layers in perovskite solar cells deliver power conversion efficiencies comparable with the commonly used reference TiO2 compact layers grown from a metal‐organic precursor (titanium diisopropoxide bisacetylacetonate, Ti(OPri)2(acac)2) that generally leaves residual carbon in the films.
ISSN:1438-1656
1527-2648
DOI:10.1002/adem.201801196