Implicit
Tandem Organic–Inorganic Hybrid Perovskite
Solar Cells Based on Internal Dye Sensitization: Robotized Screening,
Synthesis, Device Implementation, and Theoretical Insights
posted on 2020-10-15, 16:11authored byAllan Starkholm, Lars Kloo, Per H. Svensson
Low-dimensional hybrid perovskite
materials offer significantly
improved stability as well as an extensive compositional space to
explore. However, they suffer from poor photovoltaic performance as
compared to the 3D perovskite materials because of poor charge-transport
properties. Herein, we present the concept of internal dye-sensitized
hybrid perovskite compounds involving five novel low-dimensional perovskite-type
materials 1–5 incorporating triarylmethane,
phenazinium and near-infrared (NIR) cyanine cationic dyes, respectively.
The synthesis characterization and theoretical analysis of these compounds
are presented. Theoretical calculations provide interesting insights
into the effects of these dyes on the band structure of the low-dimensional
anionic metal-halides and especially highlight compound 1 as a promising photovoltaic candidate. Solar cell investigation
of devices based on 1 were conducted. The results show
an average power conversion efficiency (PCE) of about 0.1%, which
is among the highest reported for a 1D material despite the use of
undoped Spiro-OMeTAD as the hole-transport material (HTM). Incident
photon-to-electron efficiency (IPCE) spectra confirm the contribution
of the dye to the overall photocurrent of the solar cell. Moreover,
examination of solar cell devices based on the bismuth-based compound 5 resulted in PCEs in the range of 0.1%. This illustrates
the potential of this concept to be exploited for lead-free photovoltaics.
Finally automated robotized screening of low-dimensional hybrid perovskite
materials through the screening robot PROTEUS has emerged as a powerful
tool in the search for novel perovskite-like materials. Our work highlights
that the use of cationic dyes could induce interesting sensitizing
properties to low-dimensional metal-halide chains and may therefore
provide inspiration and new design strategies for the synthesis of
new lead-free photovoltaic materials