As part of a collaborative study by Pavia University (Italy) and the Center for Advancing Electronics Dresden at Technische Universität Dresden (Germany), scientists created an innovative technique to develop lead halide perovskite solar cells with efficiency like never before.
The breakthrough has been reported in Science Advances, a renowned journal. Researchers have intensively explored metal halide perovskites in the past 10 years. This is because of the phenomenal increase in their performance when used in optoelectronic devices like light-emitting diodes or solar cells.
The most efficient devices developed in what is called a “standard architecture” often involve processing steps carried out at a high temperature, which increases their energy payback time and restricts the potential to combine them in novel applications like wearable and flexible electronics.
An alternative device architecture — named the “inverted architecture” — avoids the need for processing at high temperatures, but usually results in lower photovoltaic efficiency. The researchers from the University of Pavia and the Technische Universität Dresden have devised a novel method to considerably enhance the efficiency of inverted architecture solar cells.
The technique works based on the alteration of the interfaces of the perovskite active layer by adding small amounts of organic halide salts at the bottom and the top of the perovskite layer.
Such organic halide salts are essentially used for fabricating two-dimensional perovskites and inhibit microstructural flaws and defect passivation in the perovskite layer. The researchers used this technique to achieve a power conversion efficiency of 23.7% — the highest observed so far for a perovskite solar cell with an inverted architecture.
Importantly, the improvement in performance is accompanied by an increase in device stability.
Giulia Grancini, Associate Professor of Chemistry, University of Pavia
Given that stability is one of the main hurdles for commercializing perovskite solar cells, the concurrent enhancement of stability and efficiency is specifically promising.
The fact that our devices are fabricated at low temperatures of less than 100° C and that our approach is fully applicable to the fabrication of large area devices takes us one step closer to large-scale utilization of perovskite solar cells.
Yana Vaynzof, Professor and Chair for Emerging Electronic Technologies, Institute for Applied Physics and Photonic Materials and the Center for Advancing Electronics Dresden
The never-before efficiency realized by the scientists pushes perovskite solar cells to new boundaries. Given the improved scalability and stability of the innovative approach, perovskite solar cells could be deployed on every rooftop in a few years.
Degani, M., et al. (2021) 23.7% Efficient inverted perovskite solar cells by dual interfacial modification. Science Advances. doi.org/10.1126/sciadv.abj7930.