Adding “self-healing” polymer may prevent lead leakage

Researchers from the Okinawa Institute of Science and Technology Graduate University (OIST) have found that a protective layer of epoxy resin helps prevent the leakage of pollutants from perovskite solar cells (PSCs). Adding a “self-healing” polymer to the top of a PSC can drastically reduce how much lead it discharges into the environment. This may give a boost to prospects for commercializing the technology.

A protective layer of epoxy resin helps prevent the leakage of pollutants from perovskite solar cells

“Although PSCs are efficient at converting sunlight into electricity at an affordable cost, the fact that they contain lead raises considerable environmental concern,” explains Professor Yabing Qi, head of the Energy Materials and Surface Sciences Unit, who led the study. "While so-called ‘lead-free’ technology is worth exploring, it has not yet achieved efficiency and stability comparable to lead-based approaches. Finding ways of using lead in PSCs while keeping it from leaking into the environment, therefore, is a crucial step for commercialization.”

New process yields oxide perovskite crystals in flexible, free-standing layers

Researchers at the University of California, Irvine and other institutions have developed a new process for producing oxide perovskite crystals in flexible, free-standing layers.

“Through our successful fabrication of ultrathin perovskite oxides down to the monolayer limit, we’ve created a new class of two-dimensional materials,” said co-author Xiaoqing Pan, professor of materials science & engineering at UCI. “Since these crystals have strongly correlated effects, we anticipate they will exhibit qualities similar to graphene that will be foundational to next-generation energy and information technologies.”

New technology produces perovskite quantum dots with excellent color purity and stability

A Taiwan-based research team has developed spray synthesis technology for producing perovskite quantum dots (PQDs). The technology reportedly features a photoluminescence quantum yield rate of nearly 100% and high color purity and stability of PQDs, according to Ministry of Science and Technology (MOST), which sponsors the R&D project.

Using spray synthesis technology, nanometer-sized perovskite crystals are separated from perovskite precursors in solvent and then the crystals are centrifuged to extract PQDs of same sizes, said Lin Hao-wu, which leads the team from the Department of Material Science and Engineering, National Tsing Hua University (NTHU).

Israeli-German researchers demonstrate continuous lasing action in devices made from perovskite materials

A collaborative study between Tel Aviv University (TAU) in Israel and Karlsruhe Institute of Technology (KIT) in Germany demonstrates remarkable continuous lasing action in devices made from perovskites.

"In contrast to previous studies around the world, this is the first study to exhibit continuous lasing action, as opposed to pulsed operation," says Prof. Jacob Scheuer of TAU's Department of Physical Electronics, who led the TAU team of researchers. "This family of materials is considered the most promising candidate for a future laser-based industry, because their fabrication is simple, fast and inexpensive compared to current semiconductor materials being used for these purposes. In addition, these materials can support the realization of solid-state lasers emitting in green, necessary for future lighting, displays and projectors," Prof. Scheuer adds. "Current semiconductor lasers emit light only in red and blue."

Achieving 26.0% efficient monolithic perovskite silicon tandem solar cells and analyzing the performance as a function of photocurrent mismatch

Researchers from Helmholtz-Zentrum Berlin (HZB), Eindhoven University of Technology and Technical University Berlin have combined rear junction silicon heterojunction bottom cells with p–i–n perovskite top cells into highly efficient monolithic tandem solar cells with a power conversion efficiency (PCE) of 26.0%.

The influence of current mismatch on device performance in tandem perovskite silicon solar cells imageColored cross sectional SEM image of the top cell (upper panel) and back side of the bottom cell (lower panel) of a typical monolithic tandem solar cell used in this work. (b) schematic device layout of the tandem architecture utilized in this work.

Starting from a certified efficiency of 25.0%, further improvements have been reached by reducing the current mismatch of the certified device. The top contact and perovskite thickness optimization allowed increasing the JSC above 19.5 mA cm−2, enabling a remarkable tandem PCE of 26.0%, however with a slightly limited fill factor (FF).