Role of transport layers in efficiency enhancement of perovskite solar cells

Solar power is a prominent key to clean and renewable source of electricity employed to reduce the pollution triggered by non renewable energy sources. The modern era and our future clearly depend on the efficient and economical use of solar power and other renewable sources of energy. These days, creating photovoltaic systems with next generation solar cells is a major area of focus for the energy sectors. As the next generation solar cells, perovskite solar cells have drawn a lot of interest because of their easy large scale production technique, low cost of fabrication, excellent optoelectronic features, and low temperature solution processing. These have achieved power conversion efficiency up to 27 % in the previous 15 years, but for further efficiency enhancement, the process of efficient charge carrier generation, extraction, transportation and stability under various conditions are crucial. The key issues of these cells are less control on layer's morphology, openness to humidity and oxygen, device instability and deterioration. Extensive research has been conducted to tackle these problems by utilising suitable electron and hole transport layers those can improve and prevent the charge carrier extraction and trapping and boosts the efficiency of the device concerned. Accordingly, this review summarises recent research trends on various types of electron and hole transport layers applied in perovskite solar cell devices and their role in improving the device performance. This study also aligns with Sustainable Development Goal 7 emphasizing access to affordable, reliable, and clean energy to support both the human well-being and industrial progress.