The interfacial contact between a perovskite and a carbon layer significantly affects the photovoltaic performance of a paintable and carbon-based hole transport material (HTM)-free perovskite solar cell (PSC).However,the detailed mechanism of the performance degradation,with regard to the carrier dynamics behavior at the perovskite/carbon interface,has not been elucidated yet.In this study,the improved interface of the perovskite/carbon was designed via a newly carbon electrode with nanosized carbon black and carbon fibers.Meanwhile,the Mott-Schottky analysis is conducted to study the carrier dynamics in the coherent and sparsely contacting interfaces,revealing that the unrestricted excitons in the nanoscale non-contact region of the coherent interface can be separated and then drove to be transported by the lateral built-in electric field.Furthermore,the HTM-free PSC via improved material design and fabrication by using a bilayer carbon electrode (coherent layer and conductive layer) results in an enhanced champion efficiency of 14.1%.