• Hanergy's US subsidiary MiaSole has reported achieving 23% power conversion efficiency for a flexible CIGS and perovskite tandem solar cell
  • It was achieved using Solliance’s perovskite solar cell on top and MiaSole’s CIGS cell on the bottom
  • The Hanergy subsidiary says the tandem cell performance gain was due to process improvements in the bottom CIGS cell

In January 2019, US based flexible solar cell company MiaSole Hi-Tech and European Solliance Solar Research reported 21.5% power conversion efficiency for a perovskite and flexible CIGS tandem cell (see 21.5% Efficiency For Flexible Tandem Cell).

Eight months down the line, the two companies have exceeded that mark and recorded a conversion efficiency of 23%, putting a semi-transparent perovskite solar cell on the top and a flexible CIGS cell on the bottom, calling it a ‘new world record efficiency’ for ‘flexible perovskite/CIGS-tandem solar cells’. However, Hanergy did not say in the press release that the efficiency measurement was independently confirmed.

Hanergy subsidiary MiaSole deposited the Solliance’s perovskite solar cell on a transparent and flexible substrate and employed transparent conductive electrodes. It was optimized for maximum visible light conversion efficiency and infrared light transparency to allow the majority of infrared light to reach the bottom CIGS cell.

“This significant tandem cell performance gain was achieved through process improvements in the bottom CIGS cell,” said Dmitry Poplavskyy, Director of Technology at MiaSolé Hi-Tech. “These process changes, implemented by MiaSolé, enable high efficiency CIGS cells with the spectral response better matched to the top perovskite cell. Further improvements in spectral matching as well as overall higher CIGS cell efficiency are expected to push the tandem architecture well beyond 23%.”

The CIGS cell of Miasole had its 17.44% aperture area efficiency for commercial size PV modules independently confirmed by Germany’s Fraunhofer ISE in July 2019 (see Fraunhofer Confirms MiaSole’s 17.44% Efficiency Record).