An international research team has produced translucent perovskite solar cells to maintain decent average visible transmittance (AVT) while offering higher efficiency. They tested different module and cell configurations and produced a bipolar, perovskite-perovskite tandem device with an efficiency of 17.7% at 12% AVT.
“When translucent perovskite multijunction devices have been designed and recognized as a promising path to high efficiency neutral color transparent PV, the tolerance / complex perovskite tandem stacks against a broad laser stripIt has not yet been studied,” the research team said.
The researchers concluded that the cells so far have provided decent power conversion efficiency while maintaining a high average visible transmittance (AVT). They used to a custom laser writing setup manufactures a perovskite solar cell pinch architecture and an active surface area of 0.105 cm 2. The device is based on an indium tin oxide (ITO) substrate, hole transport layer of carbazole (2PACz), electron transport layer of buckminsterfullerene (C60), absorber based on methylammonium lead triiodide (CH3NH3PbI3), a bathocuproin (BCP) buffer layer and a gold (Au) metal contact.
They expanded the cell in the area 40 times 4 cm2 to achieve an AVT 30%. They combined four of these cells into a mini-module with an area of 20 mm x 4 mm.
“The monolithic serial interfaces are fabricated by laser scribing the established P1-P2-P3 lines,” they explained.
The efficiency of the mini panel is 9.0% at 32% AVT, open circuit voltage 5.5 V, short circuit current density / 11.1mA cm2 and a fill factor of 74%.
The group also built a bipolar (2T) tandem perovskite-perovskite solar cell with a power conversion efficiency of up to 17.7% with 12% AVT. It also achieved open circuit voltage 1.95 V, short circuit current 11.9 mA cm2 and a fill factor of 77%.
“After further scale-up, a transparent tandem mini-module with 12.25 cm 2 aperture area, similar device architecture and fabricated using fully scalable coating methods offers promising 10.3% efficiency with 15% AVT and further optimizations,” they said.
The group claims that the cells are the best performing translucent perovskite tandem solar cells produced so far at the research level.
“The devices show good electrical performance of the successfully implemented permeability as well as a uniform optical impression gradients, Versatile laser-written translucent photovoltaics make it possible,” they said.
They described cell technology in the book “Transparent Perovskite Solar Cells for Building Integration,” which was published recently Royal Society of Chemistry.