title: Low-temperature-processed efficient semi-transparent planar perovskite solar cells for bifacial and tandem applications.
abstract: Semi-transparent perovskite solar cells are highly attractive for a wide range of applications, such as bifacial and tandem solar cells; however, the power conversion efficiency of semi-transparent devices still lags behind due to missing suitable transparent rear electrode or deposition process. Here we report a low-temperature process for efficient semi-transparent planar perovskite solar cells. A hybrid thermal evaporation-spin coating technique is developed to allow the introduction of PCBM in regular device configuration, which facilitates the growth of high-quality absorber, resulting in hysteresis-free devices. We employ high-mobility hydrogenated indium oxide as transparent rear electrode by room-temperature radio-frequency magnetron sputtering, yielding a semi-transparent solar cell with steady-state efficiency of 14.2% along with 72% average transmittance in the near-infrared region. With such semi-transparent devices, we show a substantial power enhancement when operating as bifacial solar cell, and in combination with low-bandgap copper indium gallium diselenide we further demonstrate 20.5% efficiency in four-terminal tandem configuration.
authors.affiliation: Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, 8600 Duebendorf, Switzerland.
authors.forename: Fan
authors.initials: F
authors.lastname: Fu
authors.affiliation: Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, 8600 Duebendorf, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Feurer
authors.affiliation: Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, 8600 Duebendorf, Switzerland.
authors.forename: Timo
authors.initials: T
authors.lastname: Jäger
authors.affiliation: Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, 8600 Duebendorf, Switzerland.
authors.forename: Enrico
authors.initials: E
authors.lastname: Avancini
authors.affiliation: Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, 8600 Duebendorf, Switzerland.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Bissig
authors.affiliation: Laboratory for High Performance Ceramics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, 8600 Duebendorf, Switzerland.
authors.forename: Songhak
authors.initials: S
authors.lastname: Yoon
authors.affiliation: Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, 8600 Duebendorf, Switzerland.
authors.forename: Stephan
authors.initials: S
authors.lastname: Buecheler
authors.affiliation: Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, 8600 Duebendorf, Switzerland.
authors.forename: Ayodhya N
authors.initials: AN
authors.lastname: Tiwari