Perovskite solar cells (PSCs) have been made eligible for proficient power conversion efficiency (PCE) by optimizing the perovskite film's morphology, formation, interfaces, and charge collection for increased effectiveness. This paper applied a new method for Cu2O/methylammonium lead iodide (MAPbI(3))/SiO2 structure with heterojunction PSCs. This paper developed a novel synthesis engineering method for thin Cu2O hole-transporting material layer (HTML) and ultrathin SiO2 electron-transporting material layer (ETML). Cu2O HTML and SiO2 ETML could improve the PCE and carrier charge for recombination and recollection. The architecture includes a reduced film thickness by hetero-contact synthesis engineering, which resulted in an impactful enhancement of open-circuit voltage (Voc). The stable Voc effect was induced by constructing the interfilm of Cu2O and SiO2 between the main CH3NH3PbI3 layers, which transported electrons/electron holes, resulting in an excellent PCE of 18.4%. The fabrication showed that inorganic materials can be applied for the potential interfacial engineering of perovskite-based solar cells.