Since 2009, power conversion efficiencies (PCE) of perovskite solar cells (PSCs) has been rising from the initial 3.8% to the state-of-the-art 25.7% within over the past 10 years. Most highly efficient PSCs utilize an n-type layer of mesoporous titanium dioxide or tin oxide in an n-i-p device configuration, in which organic conductors are widely used to transport holes into an adjoined metal. Thus far, a variety of efforts have been devoted to achieve a defect-less perovskite film with high-quality morphologies for realizing reduced loss-in-potential outcomes and enhanced efficiency levels. As a result, these holistic advancements in interface engineering, composition engineering, and charge-transporting layer engineering for perovskite solar cells enable us to achieve a PCE of over 25%. In this talk, I will briefly introduce our recent advances and understanding of the limitation to improving the photovoltaic performance further.[1,2] In particular, I will focus on talking about molecular engineering of interface modifiers and charge-transporting layers for enhancing both efficiency and stability of perovskite solar cells.[3]