Boosting thin-film perovskite solar cell efficiency through vacuum-deposited sub-nanometer small-molecule electron interfacial layers

In this paper, we demonstrate that the performance of perovskite solar cells can be largely boosted with sub-nm pyridine-containing small-molecule electron interfacial layers. These vacuum-deposited sub-nm layers between perovskites and electron transport layers create a permanent dipole moment that improves the interfacial energy level alignment and facilitates a fast electron sweep-out. With these interfacial layers, the devices exhibit exceptional power conversion efficiencies up to 18.8%, a 25% increase compared to that of the one without the interfacial layer.