HZB team brings the efficiency of perovskite silicon tandem solar cells to 29.15%

An HZB research and development team has reached a record efficiency of 29.15% of its tandem solar cell made of perovskite and silicon.

HZB team sets new efficiency record for perovskite-silicon cells imageThe illustration shows the structure of the tandem solar cell: between the thin perovskite layer (black) and the silicon layer (blue) are functional intermediate layers. © Eike Köhnen/HZB

The groups of Steve Albrecht and Bernd Stannowski have developed the tandem solar cell, which converts 29.15 percent of the incident light into electrical energy. This value is officially certified by the CalLab of the Fraunhofer Institute for Solar Energy Systems (ISE).

Japanese manufacturer acquires rights to produce CIGS perovskite cell with 23.26% efficiency developed by HZB and Kaunas University

In September 2019, a research team led by Prof. Steve Albrecht from the HZB (in close collaboration with Kaunas University of Technology in Lithuania) announced a tandem solar cell with certified efficiency of 23.26% that combines the semiconducting materials perovskite and CIGS. Now, the team shares further details on these cells and states that an unnamed Japanese manufacturer has acquired the rights to produce them.

World record for tandem perovskite-CIGS solar cell image

The scientists said the self-assembling material used for the cell is made of molecules based on carbazole head groups with phosphonic acid anchoring groups, and consists of 1-2nm of self-assembled monolayers deposited on the surface of the perovskite by dipping it into a diluted solution.

Perovskites may be used for various thermoelectric applications

A Cornell-led team of scientists has discovered a crystalline material with ultralow thermal conductivity, which could lead to the design of novel energy conversion materials and devices.

After studying a popular hybrid perovskite and identifying the mechanisms for its low thermal conductivity, Zhiting Tian, assistant professor of mechanical and aerospace engineering at Cornell, turned her attention to a hybrid perovskite analogue, methylammonium bismuth iodide (CH3NH3)3Bi2I9, which she hypothesized would have an even lower thermal conductivity because of the unique disconnected structure of its inorganic molecules.

Addition of biological material boosts performance of perovskite solar cells

An international team of researchers, including ones from Penn State, Columbia University, University of Toledo, Northeastern University in the U.S and Carl von Ossietzky University in Germany, designed next-gen solar cells that mimic photosynthesis with a biological material, by adding the protein bacteriorhodopsin (bR) to perovskite solar cells.

Power conversion efficiency (PCE) distribution of bR-incorporated PSC imagePower conversion efficiency (PCE) distribution of bR-incorporated PSC based on statistics of 15 devices, with average efficiency of 16.34 %. Image from ACS article

“These findings open the door for the development of a cheaper, more environmentally friendly bioperovskite solar cell technology,” said Shashank Priya, associate vice president for research and professor of materials science at Penn State. “In the future, we may essentially replace some expensive chemicals inside solar cells with relatively cheaper natural materials.”

2D MXenes may improve perovskite solar cell efficiency

Researchers at the University of Rome Tor Vergata in Italy and Russia’s NUST MISIS institute have investigated how cells containing two-dimensional titanium-carbide MXene support layers could improve perovskite solar cell performance.

To obtain good power conversion within a perovskite solar cell, all layers and layer interfaces within the cell must have good compatibility. Typical cells contain the active perovskite material sandwiched between two charge transport layers, which are then adjacent to their corresponding electrodes. Support layers may also be added. Charge mobility, energy barriers, interface energy alignment, and interfacial vacancies all impact compatibility and subsequent cell performance and stability. Thus, engineering well-suited interfaces with the cell is paramount to cell success and long-term stability, an important criterion for potential commercialization.