Surface Engineering of PTAA by adding Al2O3interfacial layer for Inverted Perovskite Solar Cell

Perovskite solar cells (PSCs) have shown an enormous potential due to their excellent performance and simple architecture with low temperature and solution processing compatibility. PTAA, with good stability and well-matched energy levels, becomes a superior hole transport candidate for inverted PSC devices, however, its hydrophobic nature brings some processing problems. To address this dilemma, we adopt mesoporous Al
2
O
3
nanocrystal as an interface control layer to modulate the wettability of perovskite solution. It has been demonstrated that the Al
2
O
3
interfacial layer decreases the surface energies of PTAA and enables a better homogeneous perovskite film with improved coverage and increased crystallite size.