Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - PerovskiteHTM (New Hole-Transport Materials to Enhance Perovskite Solar Cells)

Teaser

The world demand for energy is growing intensively and continuously. This creates needs for environmentally-clean energy resources like solar energy, which huge potential remains unexploited. Silicon-based solar cells consist of more than 90% of commercial photovoltaic...

Summary

The world demand for energy is growing intensively and continuously. This creates needs for environmentally-clean energy resources like solar energy, which huge potential remains unexploited. Silicon-based solar cells consist of more than 90% of commercial photovoltaic devices. However, emerging lead-halide perovskite solar cells are a potentially-revolutionary new photovoltaic technology with its advantages like: low-cost, easy-to-assemble, flexible, lightweight, semi-transparency, solution processability and freedom of design in terms of colours and shapes. This should lead to higher adoption of solar technology. Great advances in recent years have arisen mainly through developments in the light-absorbing perovskite layer, and this has created a need to develop other component materials in order to further increase device efficiency and stability. To enable the full potential of the technology to be realised progress is needed to tackle these points:
1. One of the conducting layers in the cells, the “organic hole-transport material”, currently shows poor conductivity and/or high synthesis cost and improved materials are required.
2. Poor moisture stability of the perovskite limits device lifetime.
Discovery of the hole-transport material that are both efficient and cost effective while do not decrease device stability as currently used spiro-MeOTAD remains one of the biggest challenges in the field of perovskite solar technology.

Work performed

Through careful design and synthesis, a catalogue of new conducting layers with a variety of electronic energy levels, thermal stability, processability and hydrophobicity has been developed. Their basic properties in terms of utilization in perovskite solar cells have been studied. Moreover, protocols to improve the solubility of these materials were introduced, thereby facilitating their potential application by solution printing methods. In order to increase device stability, efficiency and reproducibility of solar cells made using these materials, well controlled procedures for chemical doping have been applied. These new materials were screened in cells with appropriate doping studies. New easy to modify core for optoelectronic materials has been introduced. All these studies were conducted in strong collaboration with our partners. This work has been disseminated at numerous scientific conferences and meetings. Protocols for the synthesis of new materials, their properties and performance were published in scientific journals.

Final results

Overall the outcome of the project provides better understating of material structure-property relationship for charge conductors in perovskite solar cells, and has provided at least one material with performance/cost better than state-of-the art at the outset of the work.