Inverted perovskite-silicon tandem solar cell with 29.3% effectiveness

• Researchers in Saudi Arabia have built an inverted perovskite-silicon tandem device with a 1 nm thick interlayer based on magnesium fluoride (MgFx). They declare it can quit voltage losses and boost power conversion performance, while preserving 95.4% of its initial performance after 1,000 hrs.

Scientists at King Abdullah University of Science and also Technology (KAUST) have created an inverted perovskite-silicon tandem solar cell with a 1 nm thick interlayer based on magnesium fluoride (MgFx) positioned in between the perovskite layer as well as the hole transportation layer (HTL), in order to reduce voltage losses.

"The long-lasting study goal of the KAUST's KPV-LAB is to create a sensible high-efficiency solar service for warm and hot climates and our gadget is in line with this objective," scientist Erkan Aydin informed pv magazine.

The cell has a p-i-n framework and relies on an interlayer that provided high transparency, high stability, as well as great thickness control.

"We demonstrated that the fee transport as well as recombination user interfaces could be very carefully tuned with MgFx interlayers, making it possible for a licensed efficiency of 29.3%," the scientists said.

Currently, one of the most effective perovskite/silicon tandem solar cell is a 29.8% gadget that was lately created by scientists at Helmholtz-Zentrum Berlin (HZB) in Germany.

The Saudi researchers produced the cell with a sub-cell based on crystalline silicon wafers with double-side structure, which they claim decreases front reflection while boosting light capturing. They likewise placed the MgFx interlayer at the electron-selective top get in touch with.

They used buckminsterfullerene, a molecule which is also known as C60, for the manufacture of the HTL, and also included a tin(IV) oxide (SnO2) layer and an indium tin oxide (IZO) leading get in touch with. The Sno2 layer works as a buffer against damage from the sputtering of the IZO top call. This IZO-perovskite structure, according to the scientists, sustained an extremely slow carrier degeneration process and also enhanced charge removal.

The researchers tested an enveloped solar cell built with this architecture at the CalLab of the Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) in Germany. The gadget attained a steady-state power conversion effectiveness of 29.3% as well as a reverse-scan effectiveness of 29.4%. It additionally achieved an open-circuit voltage of 1.85 V, a short-circuit current of 19.8 mA/cm2, and also a fill element of 77.9%.

"The gadget data supported that the power conversion effectiveness improvement was mostly the outcome of enhanced open-circuit voltage and also fill aspect," they described.

The cell experienced damp-heat screening and also was able to retain 95.4% of its preliminary performance after 1,000 hrs.

"The open-circuit voltage even boosted slightly, suggesting that the perovskite itself and the interfacial layers were sufficiently tolerant to thermal tension," the research study group claimed.

The academics offered the cell in "Efficient as well as stable perovskite-silicon tandem solar cells via get in touch with displacement by MgFx," which was lately released in Science.

"Looking forward, our overall goal is to boost the performance and also security as high as possible and also drive down the [levelized price of electrical power] listed below the current mainstream crystalline silicon solar cells," Aydin said.

In December 2021, the same research team accomplished a power conversion effectiveness of 28.2% for a tandem solar cell with an area of around 1 square centimeters, based upon an n-i-p perovskite piled on top of a silicon heterojunction. The performance was accomplished with an unique technique to reduce halide segregation and also reduce nonradiative recombination loss. The approach includes making use of carbazole, a nitrogen-containing heterocyclic molecule, as an additive for the cell perovskite precursor.