Printing solar cells and organic LEDs
The HySPRINT logo (Helmholtz Innovation Lab) printed on a copper solution symbolizes how the thinnest material layers can be produced simply and cost-effectively. Possible applications are solar cells, organic LEDs or transistors. Photo © Humboldt-Universität zu Berlin/List-Kratochvil
Humboldt-Universität zu Berlin and Helmholtz-Zentrum Berlin form a joint lab and research group “Generative production processes for hybrid components”.
Solar cells, LEDs and detectors made of organic and hybrid semiconductors can nowadays be simply printed out, even together with teensy nanostructures that make them function better. The development of low-cost printing methods for electronic and optoelectronic components is at the centre of things for the new joint research group and the joint laboratory of the Helmholtz-Zentrum Berlin (HZB) and Humboldt-Universität zu Berlin (HU).
Cooperating together in the new research group are the HU workgroup “Hybrid Devices” led by Prof. Dr. Emil List-Kratochvil, the HZB young investigator group of Dr. Eva Unger, the Helmholtz Innovation Lab HySPRINT, and the Competence Centre Photovoltaics Berlin (PVcomB) directed by Prof. Dr. Rutger Schlatmann. The partners are building up a joint lab at Humboldt-Universität zu Berlin that will allow the researchers to acquire and use complementary laboratory infrastructures for various coating methods.
Prof. Emil List-Kratochvil is the head of the HU workgroup “Hybrid Devices” at IRIS Adlershof, and has been working for 15 years on developing electronic and optoelectronic hybrid components, resource-efficient deposition techniques (inkjet printing) and in-situ nanostructuring and synthetic methods. This expertise complements the aims of the HZB young investigator group led by Dr. Eva Unger. She will be developing solution-based manufacturing methods for depositing perovskite semiconductor layers onto larger surface areas for solar cells. “The new research group with List-Kratochvil is a real win for us. With his experience in printed electronic components, he is an ideal cooperation partner for us,” Unger says.
In recent months, the researcher and her team have already come much closer to her goal of developing hybrid tandem solar cells with large-surface-areas in the scope of the Helmholtz Innovation Lab HySPRINT. Now, the next step is to upscale the process in order to drive the novel solar cells towards market maturity. The Competence Centre Thin-Film- and Nanotechnology for Photovoltaics Berlin (PVcomB) is the ideal partner for the development of industrially relevant manufacturing processes. The joint research group is now striving towards building a pilot line on which to develop prototypes of hybrid components.
- CIGS-perovskite tandem cell achieves record efficiency of 25.5 %A Berlin-based team from HZB and Center for the Science of Materials Berlin (CSMB) at the Humboldt-Universität zu Berlin has set a new record for a tandem solar cell. Using a combination of a CIGS semiconductor layer and perovskite, along with several optimised intermediate layers, they were able to convert 25.5% of sunlight into electrical energy. The previous record for this combination of materials and this size of cell stood at 24.6%. The new record has been certified and is visible in the prestigious Solar Cell Efficiency Tables (the "Green Tables"), which serve as the definitive ledger for the global photovoltaic community.
- Disorder creates new properties in compound semiconductorsAn international research team has demonstrated that the intrinsic disorder of the compound semiconductor CuInSnS₄ can be exploited to influence its optical properties. While the atomic vibrations also sense the local disorder, their response is averaged over many different local environments and therefore appear isotropic, as expected for a cubic crystal. In contrast, the optical excitations, known as excitons, are much more sensitive to the local arrangement of atoms. Surprisingly, they show a direction-dependent optical response even though the average crystal structure is cubic. These findings shed new light on the relationship between disorder and material properties, opening up new options for targeted 'disorder engineering' in optoelectronic and photocatalytic devices.
- Perovskite solar cells: Predictions of long-term stabilityReliable statements about the long-term stability of perovskite solar cells are still difficult to make. However, a new study by Dr Carolin Ulbrich’s team, published in the renowned journal Joule, highlights which methods are useful for this purpose and identifies areas where further research is needed.