We
demonstrate highly efficient, stable, and flexible perovskite
solar cells of large areas, utilizing a carbon back-contact electrode
in a p–i–n cell configuration. We enabled good electronic
contact at the interface with carbon by inserting an ultrathin buffer
layer before the carbon coating. Solar cells of such structure reach
a power conversion efficiency of 15.18% on PET foil (device area of
1 cm2). We performed impedance spectroscopy and transient
decay measurements to understand the electron transport characteristics.
Furthermore, we demonstrate excellent operational (maximum power point)
and thermal (85 °C) stability of these devices over 1000 h of
aging.
Metal halide perovskites have raised huge excitement in the field of emerging photovoltaic technologies. The possibility of fabricating perovskite solar cells (PSCs) on lightweight, flexible substrates, with facile processing methods, provides very attractive commercial possibilities. Nevertheless, efficiency values for flexible devices reported in the literature typically fall short in comparison to rigid, glass-based architectures. Here, a solution-processable fullerene derivative, [6,6]-phenyl-C61 butyric acid n-hexyl ester (PCBC6), is reported as a highly efficient alternative to the commonly used n-type materials in perovskite solar cells. The cells with the PCBC6 layer deliver a power conversion efficiency of 18.4%, fabricated on a polymer foil, with an active area of 1 cm 2. Compared to the phenyl-C61-butyric acid methyl ester benchmark, significantly enhanced photovoltaic performance is obtained, which is primarily attributed to the improved layer morphology. It results in a better charge extraction and reduced nonradiative recombination at the perovskite/ electron transporting material interface. Solution-processed PCBC6 films are uniform, smooth and displayed conformal capping of perovskite layer. Additionally, a scalable processing of PCBC6 layers is demonstrated with an ink-jet printing technique, producing flexible PSCs with efficiencies exceeding 17%, which highlights the prospects of using this material in an industrial process.
Perovskite solar
modules (PSMs) have been attracting the photovoltaic
market, owing to low manufacturing costs and process versatility.
The employment of flexible substrates gives the chance to explore
new applications and further increase the fabrication throughput.
However, the present state-of-the-art of flexible perovskite solar
modules (FPSMs) does not show any data on light-soaking stability,
revealing that the scientific community is still far from the potential
marketing of the product. During this work, we demonstrate, for the
first time, an outstanding light stability of FPSMs over 1000 h considering
the recovering time (
T
80
= 730 h), exhibiting
a power conversion efficiency (PCE) of 10.51% over a 15.7 cm
2
active area obtained with scalable processes by exploiting blade
deposition of a transporting layer and a stable double-cation perovskite
(cesium and formamidinium, CsFA) absorber.
A new series of diacetylide-triphenylamine (DATPA) derivatives with five different alkyl chains in the para position, MeO, EtO, PrO,PrO and BuO, were synthesised, fully characterised and their function as hole-transport materials in perovskite solar cells (PSC) studied. Their thermal, optical and electrochemical properties were investigated along with their molecular packing and charge transport properties to analyse the influence of different alkyl chains in the solar cell parameters. The shorter alkyl chain facilitates more compact packing structures which enhanced the hole mobilities and reduced recombination. This work suggests that the molecule with the methoxy substituent (MeO) exhibits the best semiconductive properties with a power conversion efficiency of up to 5.63%, an open circuit voltage (V) of 0.83 V, a photocurrent density (J) of 10.84 mA cm and a fill factor of 62.3% in perovskite solar cells. Upon replacing the methoxy group with longer alkyl chain substituents without changing the energy levels, there is a decrease in the charge mobility as well as PCE (e.g. 3.29% for BuO-DATPA). The alkyl chain length of semiconductive molecules plays an important role in achieving high performance perovskite solar cells.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.