Researchers from King Abdullah University of Science and Technology (KAUST) have fabricated efficient, two-terminal monolithic perovskite-silicon tandem solar cells and tested them outdoors. The tandem device that resulted from this research was found to be more stable than conventional perovskite cells and, importantly, optimized for use in industry.

Perovskite/silicon cells under test at KAUST outdoor facility

The findings of KAUST Research Scientists Dr. Erkan Aydin and Dr. Thomas Allen, and colleagues in Professor Stefaan De Wolf's group, indicate that the temperature dependence of both the silicon and perovskite bandgaps—which follow opposing trends—shift the current-matching-optimization point away from that for two-terminal tandems under standard test conditions.

A research team from the Shanghai Institute of Optics and Fine Mechanics has recently demonstrated perovskite CQDs (colloidal quantum dots) single-mode laser with good performance across the entire visible spectra range.

In this study, a composited microcavity was obtained through the conformal deposition of cesium lead halide perovskite (LHP) CQDs on a high quality individual sub-micron ZnO rod by dip-coating self-assembled techniques. A single-mode lasing with high quality factor and low threshold was obtained.

Scientists from City University of Hong Kong (CityU) recently developed a novel method which can simultaneously tackle both the lead leakage issue of perovskite solar cells and the stability issue without compromising efficiency, paving the way for real-life application of perovskite photovoltaic technology.

Perovskite solar cells tend to contain lead components, which raise concerns for potential environmental contamination. "As the solar cell ages, the lead species can leak through the devices, e.g. through rainwater into the soil, posing a toxicity threat to the environment," explained Professor Alex Jen Kwan-yue, CityU's Provost and Chair Professor of Chemistry and Materials Science. "To put PVSCs into large-scale commercial uses, it requires not only high power conversion efficiency but also long-term device stability and minimized environmental impact."

Researchers from Czech Republic's Charles University, University of Tennessee and Oak Ridge National Laboratory in the U.S have explored the dynamics of free holes in methylammonium lead tribromide (MAPbBr₃) single crystals using time-of-flight (ToF) current spectroscopy. The team's results provide insights on the charge transport properties of perovskite semiconductors.

By combining ToF spectroscopy and Monte Carlo simulation, three energy states were detected in the bandgap of MAPbBr₃. In addition, the team found the trapping and detrapping rates of free holes ranging from a few microseconds to hundreds of microseconds. It was revealed that a strong detrapping activity of traps exists.