New approach uses crown ethers to improve perovskite solar cell stability

Researchers from EPFL, Universität Tübingen and University of Fribourg, led by Professor Michael Grätzel at EPFL’s School of Basic Sciences, used a novel method with multimodal host-guest complexation to significantly improve the stability of perovskite solar cells while also reducing the release of lead into the environment. The strategy involves using a member of the crown ethers, a family of cyclic compounds whose ring-like atomic structure resembles a crown.

The researchers used the dibenzo-21-crown-7 in the fabrication of formamidinium lead iodide perovskite solar cells. They demonstrated the efficiency of this synergistic approach with cesium metal ions, for which the crown ether shows a strong affinity. Acting as a vehicle, the crown ether assembles at the perovskite film’s interface and delivers the cesium ions into its interior.

Researchers use thermal evaporation to achieve 15% efficient 'black perovskite' solar cells

Researchers at the Dresden University of Technology (TUD) have announced the fabrication of a solar cell based on all-inorganic cesium-lead iodide (CsPbI3) perovskite, which is also sometimes referred to as 'black perovskite'.

Black perovskite solar cell with 15% efficiency via thermal evaporation imagea) Schematic of the deposition procedure (b) device structure. Image from Advanced Energy Materials

TUD researcher Yana Vaynzof said that the choice of this specific material was motivated by the fact that it shows superior stability as compared to the commonly used organic-inorganic lead halide perovskites.

Researchers at CHOSE and Saule Technologies design a large-area flexible perovskite solar module using a fully scalable deposition technique

Researchers at the University of Rome Tor Vergata's Centre for Hybrid and Organic Solar Energy (CHOSE), in collaboration with Poland-based Saule Technologies, have demonstrated a large-area flexible perovskite solar module with a fully scalable deposition technique.

Stable perovskite solar module on a flexible substrate image

The results show the optimization of PTTA and perovskite layer deposition by blade-coating, with the final fabrication of a flexible perovskite module with a PCE of 10.51% over 15.7 cm2, showing outstanding light stability of FPSM with a T80′ of 730 h and a recovery efficiency in the dark showing a T80″ of 1560 h, the most stable in the literature reported so far.

Researchers use special capping layer to achieve flexible solar cells with improved efficiency, stability and reliability

An international team of researchers, including ones from Brown University, EPFL, Dalian University of Technology and Shaanxi Normal University, has developed a flexible thin-film perovskite solar cell with an efficiency of 21.0%.

Flexible perovskite solar cells with simultaneously improved efficiency, operational stability, and mechanical reliability image

The perovskite layer for the cell, which has an “n-i-p” layout, was fabricated using a metal-halide capping layer placed on top of a three-dimensional metal-halide perovskite film. This design reportedly provides hermetically sealed encapsulation, which is traditionally difficult to achieve in flexible perovskite cells, and also enhances the photocarrier properties at the interface between the perovskite film and the hole transport layer (HTL).

Researchers use H3pp additive to improve device stability and gain better understanding of the impact of defects in PSCs

An international team of scientists from ICN2, EPFL, Eindhoven University of Technology, University of Cambridge, Max-Planck Institute for polymer Research and several other institutions have fabricated perovskite solar cells which retained almost all of their initial 21% efficiency after 1,000 hours under continuous operation at their maximum power point.

The effects of defects in PSCs image

The researchers attribute this performance to an additive that ‘blocked’ ions that cause device degradation, 3-phosphono propionic acid (H3pp), which served to greatly improve device stability with no observable effects on its solar performance. The team hopes this new work will contribute to an improved understanding of the relationship between efficiency and stability in perovskite PV.