Tandem solar cell globe record: New branch in the NREL graph

• Tandem cells combine 2 various semiconductors that convert various parts of the light spectrum into electric power. Metal-halide perovskite substances primarily make use of the noticeable parts of the spectrum, while CIGS semiconductors convert rather the infrared light.

CIGS cells, which contain copper, indium, gallium and also selenium, can be deposited as thin-films with a complete density of just 3 to 4 micrometers; the perovskite layers are also much thinner at 0.5 micrometers. The brand-new tandem solar cell made of CIGS and also perovskite therefore has a density of well listed below 5 micrometers, which would certainly enable the manufacturing of flexible solar modules.

"This combination is additionally extremely light weight and also secure versus irradiation, and also could be suitable for applications in satellite technology in space", claims Prof. Dr. Steve Albrecht, HZB. These results, acquired in a huge cooperation, have actually been simply published in the prominent journal JOULE.

"This time, we have actually attached the bottom cell (CIGS) directly with the top cell (perovskite), to ensure that the tandem cell has just 2 electric calls, supposed terminals", clarifies Dr. Christian Kaufmann from PVcomB at HZB, that created the CIGS base cell with his team as well as he adds "Especially the introduction of rubidium has actually considerably boosted the CIGS absorber material".

Albrecht and also his group have actually transferred in the HySPRINT laboratory at HZB the perovskite layer straight on the rough CIGS layer. "We used a trick that we had actually previously created," discusses previous postdoc from Albrecht's group Dr. Marko Jost, that is currently a scientist at the University of Ljubjana, Slovenia. They used so-called SAM particles to the CIGS layer, which develop a self-organised monomolecular layer, boosting the contact between perovskite as well as CIGS.

The new perovskite CIGS tandem cell accomplishes an effectiveness of 24.16 percent. This value has actually been formally licensed by the CalLab of the Fraunhofer Institute for Solar Energy Systems (ISE).

Given that such "2 Terminal" tandem cells constructed from CIGS as well as perovskite now represent a different category, the National Renewable Energy Lab NREL, USA, has created a brand-new branch on the famous NREL graph for this purpose. This graph reveals the advancement of effectiveness for mostly all solar cell kinds considering that 1976. Perovskite substances have only been included because 2013 - the performance of this material course has increased more steeply than any other product.