NU 2024-102

INVENTORS
Doekjae Choi
Bin Chen
Ted Sargent*

SHORT DESCRIPTION
This technology significantly improves the efficiency and stability of all-perovskite tandem solar cells through surface functionalization and atomic layer deposition.

BACKGROUND
Voltage deficits in inverted perovskite solar cells occurs primarily at the interface recombination between perovskite and fullerene electron transport layers. Various interface passivation strategies have been explored to reduce recombination loss at the interface mainly using a spin coating method. Atomic layer deposition (ALD) has emerged as a promising alternative enabling atomic-level control of thickness, excellent uniformity and conformality, and the use of stable metal oxides. Despite the potential of ALD for effective interface passivation, its application faces two main challenges: the direct exposure of perovskite layers to highly reactive precursors and oxidants leading to the degradation of the perovskite layers, and low temperature requirements of ALD resulting in poor uniformity due to the reduced reactivity at lower temperatures.

ABSTRACT
The technology provides a method for improved all-perovskite tandem solar cells by using atomic layer deposition (ALD) of Al₂O₃ on ammonium functionalized perovskite surfaces. This method targets the reduction of nonradiative recombination at the perovskite/electron transport layer interface, a critical factor limiting the power conversion efficiency (PCE) of these solar cells. The treatment enhances device performance and stability by improving the uniformity and quality of the Al₂O₃ layer.

ADVANTAGES

• Significant reduction in nonradiative recombination at critical interfaces.

• Improved open-circuit voltage and fill factor in single-junction devices.

• Enhanced power conversion efficiency, achieving up to 25.2% in tandem devices.

• Increased operational stability of solar cells, maintaining high efficiency over time.

APPLICATIONS

• High-efficiency solar energy systems.

• Portable and integrated solar-powered devices.

• High-efficiency, stable solar panels for harsh environments.

PUBLICATIONS

Bimolecularly passivated interface enables efficient and stable inverted perovskite solar cells

IP STATUS

US Provisional Application Filed