Researchers pinpoint surprising cause of efficiency loss in solar cells based on hybrid perovskites

Researchers at UC Santa Barbara have discovered an important factor that limits the efficiency of perovskite solar cells.

Various possible defects in the lattice of hybrid perovskites had previously been considered as the potential cause of such limitations, but it was assumed that the organic molecules would remain intact. The team has now revealed that missing hydrogen atoms in these molecules can cause massive efficiency losses.

KIT researchers demonstrate high efficiency over large area perovskite solar module

Researchers at the Karlsruhe Institute of Technology (KIT) have produced perovskite solar modules with greatly reduced loss of efficiency due to scaling. The team reported an efficiency of 18% for a perovskite solar module with an area of ​​4cm2 - a world record for vacuum-processed perovskite solar modules. To this end, they combined the series connection by laser with the vacuum processing of all layers of the solar cell.

Interconnecting cells into modules with almost no losses is achieved with an innovative combination of processes image

"One of the main challenges is to transfer the efficiencies achieved on areas of a few square millimeters to typical solar module surfaces of a few hundred square centimeters," says Dr. Tobias Abzieher, who heads the development of perovskite solar cells deposited from a vacuum at the Light Technology Institute (LTI) of the KIT. Perovskite solar cells are often joined together to form large-area solar modules using the so-called monolithic series connection. For this purpose, structuring lines are introduced during the deposition of the individual layers of the solar cell, which causes the solar cell strips to be connected in series.

Researchers report new perovskite-based synapse-like phototransistor

Researchers at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) have reported a breakthrough in energy-efficient phototransistors - devices that could someday help computers process visual information similarly to the human brain and be used as sensors in applications like self-driving vehicles.

The structures rely on metal-halide perovskites. Jeffrey Blackburn, a senior scientist at NREL and co-author of a new paper outlining the research, said: “In general, these perovskite semiconductors are a really unique functional system with potential benefits for a number of different technologies”. “NREL became interested in this material system for photovoltaics, but they have many properties that could be applied to whole different areas of science.”

UNT team uses additive manufacturing to print inks of 2D perovskites

A University of North Texas researcher and his team have reported a breakthrough in using additive manufacturing to further research into flexible solar panels.

A complete process flow of inkjet printing 2d perovskite inks image

Anupama Kaul, Professor of Engineering from the Departments of Materials Science and Engineering and Electrical Engineering, has successfully used additive manufacturing to print inks of 2D perovskites.

Researchers use pressure to manipulate the speed of the 'hot carrier cooling' process in perovskites

Researchers at AMOLF have found a way to manipulate the speed of the 'hot carrier cooling' process in perovskites. In this process, high energy photons lose their excess energy in the form of heat before being converted to electricity. In solar cells, about two thirds of the energy of sunlight is lost - and half of this loss stems from the hot carrier cooling process.

Schematic representation of the pressure-dependent fs-TA setup showing the generation of hot carriers imageSchematic representation of the pressure-dependent setup. Image from JACS article

The AMOLF team found a way to manipulate the speed of this process in perovskites, by applying pressure to the material. This paves the way for making perovskites more versatile, not only for use in solar cells but also in a variety of other applications, from lasers to thermoelectric devices.