Sungkyunkwan University Develops Scalable Inverted Perovskite Solar Cells with 27.3% Efficiency via Atomic Layer Deposition (ALD)

RSC Advances South Korea

Overview

Researchers at Sungkyunkwan University, South Korea, have developed scalable inverted perovskite solar cells (iPSCs) using atomic layer deposition (ALD), achieving 27.3% power conversion efficiency. This technology addresses the critical challenge of performance degradation during scale-up from lab-scale to large-area modules. The ALD-deposited ultrathin nickel oxide (NiO) hole-transporting layer (HTL) offers precise thickness control and high conformality, resulting in improved operational stability, low hysteresis, and compatibility with flexible substrates, making it promising for integration into tandem devices.

In Depth

Background

Perovskite solar cells (PSCs) have garnered significant attention as a next-generation photovoltaic technology due to their impressive power conversion efficiencies (PCEs). However, a major impediment to their commercialization has been the substantial performance drop observed when scaling up high efficiencies achieved in small, laboratory-scale cells to large-area modules. Challenges primarily stem from maintaining film uniformity and quality control during large-area solution processing, necessitating precise thin-film deposition techniques. Inverted PSCs (iPSCs) are particularly promising due to their superior stability and reduced hysteresis characteristics.

Key Findings / Results

A research team at Sungkyunkwan University in South Korea has successfully developed scalable inverted perovskite solar cells (iPSCs) using atomic layer deposition (ALD), a highly precise thin-film deposition technique. In their study, the researchers systematically evaluated performance across active areas of 0.06, 0.25, and 1 cm² to identify intrinsic performance losses associated with increasing device size. They adopted an innovative approach by utilizing ALD to deposit an ultrathin nickel oxide (NiO) hole-transporting layer (HTL). Compared to NiO films formed by solution processes or sol-gel methods, ALD enables precise thickness control at the nanometer level and offers excellent conformality over the substrate. This precise control led to a reduction in interface defects and optimized charge transport, resulting in a remarkably high power conversion efficiency (PCE) of 27.3%. Furthermore, the developed devices exhibited improved operational stability, low hysteresis, and compatibility with flexible substrates, also suggesting potential for integration into future tandem devices.

Technical Significance & Outlook

Sungkyunkwan University’s development of scalable iPSCs using ALD is a breakthrough in overcoming the critical challenge of large-area scaling and associated performance degradation in perovskite solar cells for commercialization. ALD is a well-established technology in the existing semiconductor industry, and its integration enhances the industrial compatibility of perovskite solar cell manufacturing processes. The precise thickness control and uniformity achieved will significantly improve the quality and yield of large-area modules, contributing to reduced manufacturing costs. This technology holds substantial promise as an effective approach for fabricating high-efficiency tandem solar cells, particularly all-perovskite tandems or perovskite/silicon tandems, as either top or bottom cells. Future efforts will involve optimizing ALD processes, applying them to actual mass production lines, and conducting long-term reliability evaluations in outdoor environments to accelerate the further adoption and societal implementation of this technology. This Korean research stands out as an example leading the industrialization of next-generation solar cells.