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.