5 research outputs found
Large Area 23%-Efficient Monolithic Perovskite/Homo-Junction-Silicon Tandem Solar Cell with Enhanced UV Stability Using Down-Shifting Material
Water-Free, Conductive Hole Transport Layer for Reproducible PerovskiteāPerovskite Tandems with Record Fill Factor
State-of-the-art perovskiteāperovskite tandem
solar cells
incorporate a water-based poly(3,4-ethylenedioxythiophene):polystyrenesulfonate
(PEDOT:PSS) hole transport layer in its low bandgap subcell. However,
there is a limitation regarding its use due to the moisture sensitivity
of perovskites and the insulating property of PSS. Here, we overcome
the limitation by using a water-free and PSS-free PEDOT-based hole
transport layer for low bandgap single-junction perovskite solar cells
and in perovskiteāperovskite tandems. The champion tandem cell
produces an efficiency of 21.5% and a fill factor of 85.8%, the highest
for any perovskite-based double-junction tandems. Results of photoelectron
spectroscopy, Fourier-transform infrared spectroscopy, and conductive
atomic force microscopy reveal evidence of enhanced conductivity of
water-free and PSS-free PEDOT compared to its conventional counterpart.
The use of water-free and PSS-free PEDOT also eliminates decomposition
of high bandgap subcell with its interfacing layer stack in a tandem
that otherwise occurs with conventional PEDOT:PSS. This leads to enhanced
reproducibility of perovskiteāperovskite tandems