2 research outputs found
Water-Free, Conductive Hole Transport Layer for Reproducible Perovskite–Perovskite Tandems with Record Fill Factor
State-of-the-art perovskite–perovskite 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 perovskite–perovskite 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 perovskite–perovskite tandems
Efficient Flexible Monolithic Perovskite–CIGS Tandem Solar Cell on Conductive Steel Substrate
Here we report for the first time a monolithic perovskite–CIGS
tandem (CIGS = Cu(In,Ga)Se2) solar cell on a flexible conductive
steel substrate with an efficiency of 18.1%, the highest for a flexible
perovskite–CIGS tandem to date, representing an important step
toward flexible perovskite-based tandem photovoltaics