Researchers deepen understanding of defects in Hybrid Perovskites

A team of researchers from HZB, CNRS and Charles University used a multi-method approach to quantify and characterize defects in single crystal MAPbI3, giving a cross-checked overview of their properties. The team characterized five different defect types and measured the interaction between these defects and the charge carriers.

MAPI semiconductors consist of organic methylammonium cations and lead iodide octahedra that form a perovskite structure. MAPI based solar cells have achieved efficiencies of 25% within a few years. But so far, the semi-organic semiconductors are still ageing rapidly.

Researchers report positive results from tests with low-cost fluorene-xantene-based HTM

Researchers at the University of Rome Tor Vergata's Centre for Hybrid and Organic Solar Energy (CHOSE) and ISM-CNR have tested a commercially available HTM with a new core made by low-cost fluorene–xantene units. The experimentation was conducted on small (0.09 cm2) and large area (1.01 cm2) cells.

The one-pot synthesis of this compound is said to drastically reduce its cost compared with the commonly used Spiro-OMeTAD. The optoelectronic performances and properties were characterized through JV measurement, IPCE (incident photon to current efficiency), steady-state photoluminescence and ISOS stability test. SEM (scanning electron microscope) images reveal a uniform and pinhole free coverage of the X55 HTM surface, which reduces the charge recombination losses and improves the device performance relatively to Spiro-OMeTAD from 16% to 17%. The ISOS-D-1 stability test on large area cells without any encapsulation reports an efficiency drop of about 15% after 1000 h compared to 30% for the reference case.

Researchers use Cesium-doped Ti3C2Tx MXene for efficient and thermally stable perovskite solar cells

Researchers from The University of Queensland, EPFL, Griffith University and NIMS have studied how doping can help in overcoming some of perovskite solar cells' drawbacks. The researchers found that the efficiency and thermal stability of the doped cells significantly outperformed those that were not doped.

Cesium-doped Ti3C2Tx MXene for efficient and thermally stable perovskite solar cells image

“The PSCs that had doped cells showed a remarkable solar conversion efficiency that exceeded 21 per cent,” the team reported.

Researchers deepen understanding of strain in in halide perovskite photovoltaics

Researchers from the University of Surrey, University of Cambridge and University of Toronto, have explained the origin, characterization, pitfalls and opportunities for strain in perovskite materials. The team also explained their vision of how the research community can use strain to unleash the full potential of perovskite materials.

Dr. Wei Zhang, a corresponding author and Senior Lecturer from the University of Surrey, said: "Many in the photovoltaic research community are rightly excited about the potential of perovskite materials, not only when it comes to green technologies such as solar cells but other electronic devices. In this study, we look at factors that influence the efficiency and stability of devices—and explore the role strain may play on perovskites. A comprehensive understanding of strain in perovskites will lead to perovskite materials with remarkable optoelectronic novelty."