2D MXenes may improve perovskite solar cell efficiency

Researchers at the University of Rome Tor Vergata in Italy and Russia’s NUST MISIS institute have investigated how cells containing two-dimensional titanium-carbide MXene support layers could improve perovskite solar cell performance.

To obtain good power conversion within a perovskite solar cell, all layers and layer interfaces within the cell must have good compatibility. Typical cells contain the active perovskite material sandwiched between two charge transport layers, which are then adjacent to their corresponding electrodes. Support layers may also be added. Charge mobility, energy barriers, interface energy alignment, and interfacial vacancies all impact compatibility and subsequent cell performance and stability. Thus, engineering well-suited interfaces with the cell is paramount to cell success and long-term stability, an important criterion for potential commercialization.

Korean team uses a transparent conductive adhesive to combine perovskite and silicon solar cells

Researchers from the Ulsan Institute of Science and Technology (UNIST) have demonstrated a new method of fabricating perovskite-on-silicon tandem devices, using a transparent conductive adhesive (TCA) to combine the two cells. The scientists have developed devices with demonstrated efficiencies of 19.4%, and propose methods to bring that up to over 24% using existing technology.

While the efficiency is still well below the 28% record for a perovskite/silicon tandem cell set by Oxford PV, the UNIST group says its method is far simpler to manufacture than previous concepts. “It is meaningful to develop an attached tandem solar cell unlike the conventional tandem solar cell with stacked structure,” said UNIST’s In Young Choi, lead author of the study. “We have observed that the TCA effectively connects the different light-absorbing layers.”

HZB researchers reach 23.26% record efficiency for tandem perovskite-CIGS solar cell

A team led by Prof. Steve Albrecht from the HZB has announced a new world-record: a tandem solar cell with certified efficiency of 23.26% that combines the semiconducting materials perovskite and CIGS. One reason for this success lies in the cell’s intermediate layer of organic molecules: they self-organize to cover even rough semiconductor surfaces. Two patents have been filed for these layers.

World record for tandem perovskite-CIGS solar cell image

Perovskite-based solar cells have experienced an incredibly rapid increase in efficiency over the last ten years. The combination of perovskites with classical semiconductor materials such as silicon and copper-indium-gallium-selenide (CIGS) compounds in tandem solar cells promises low-cost, high-performance solar modules for the future. However, losses at the electrodes between the two semiconductors considerably reduce the efficiency.

Flexible tandem perovskite/CIGS solar cells with 23% conversion efficiency reported by Solliance and MiaSolé

Solliance and U.S-based MiaSolé announced a new record - power conversion efficiency of 23% on a flexible tandem solar cell: a top flexible semi-transparent perovskite solar cell with a bottom flexible copper indium gallium selenide (CIGS) cell.

Solliance and Miasole's 23%efficiency tandem perovskite/CIGS cells image

This achievement comes only 9 months after the January 2019 announcement by Solliance and MiaSolé regarding a flexible solar cell with an impressive power conversion efficiency of 21.5%. The solar cell, similarly to this newly announced one, combined two thin-film solar cell technologies into a 4 terminal tandem solar cell stack: a top flexible semi-transparent perovskite solar cell with a bottom flexible copper indium gallium selenide (CIGS) cell.

New "Capitano" project aims to develop CIGS-perovskite tandem cells

German university the Karlsruhe Institute of Technology (KIT), the Center for Solar Energy and Hydrogen Research Baden-Würtetemburg (ZSW) and CIGS module manufacturer Nice Solar Energy have announced an ambition to design tandem PV modules based on CIGS and perovskite, which can theoretically achieve efficiencies well above 30%.

The joint ‘Capitano’ project will run for three years and has received more than €5 million from Germany’s Federal Ministry for Economic Affairs and Energy. The aim of the project is to develop cells with stable higher efficiencies, which can be interconnected to form efficient tandem solar modules.