Perovskite solar cells: Interfacial loss systems revealed

• Losses take place in all solar cells. One cause is the recombination of cost carriers at the interfaces. Intermediate layers at such interfaces can reduce these losses via so-called passivation. Self-assembled monolayers (SAMs) with a carbazole core are particularly well suited for the passivation of semiconductor surfaces constructed from perovskite products.

A team led by HZB physicist Prof. Steve Albrecht along with a team from Kaunas Technical University in Lithuania showed this a long time earlier, creating a silicon-perovskite-based tandem solar cell with a record efficiency of over 29 %.

Currently, for the very first time, a group at HZB has actually analysed the charge service provider characteristics at the perovskite/SAM-modified ITO user interface in extra detail. From time-resolved surface photovoltage measurements, they had the ability to draw out the density of "electron traps" at the interface as well as the hole transfer prices utilizing a minimalist kinetic design. Complementary details was provided by gauging the time-resolved photoluminescence.

"We were able to establish distinctions in passivation quality, selectivity and hole transfer prices depending on the structure of the SAM, and demonstrate exactly how the time-resolved surface area photovoltage and photoluminescence methods are complementary," discusses Dr. Igal Levine, postdoc at HZB and very first writer of the paper.

Time-resolved surface photovoltage proves to be a relatively basic strategy for quantifying fee removal at buried user interfaces that might dramatically help with the design of excellent charge-selective get in touches with.