Enhancing the performance of perovskite solar cells (PSCs) is one of the prime concerns of researchers worldwide. For PSC devices, it is essential to develop the individual layer efficiently and cost-effectively. This work emphasizes the possibility of employing Zn-Sn oxide-based composite materials as an alternative electron transport layer (ETL) in PSC devices. Pristine Zn 2SnO 4 (ZTO), composite ZTO-ZnO, and ZTO-SnO 2 heterostructure-based ETL were prepared by simple solid-state calcination technique and proposed as an alternative for the TiO 2 photoanode used in the PSC devices. The power conversion efficiency of the designed PSC was studied based on crystallinity, morphology, cross-section, roughness, contact angle, work function, and Raman analysis of the ETL material. TEM analysis confirms the phase pure ZTO and heterostructure formation as a function of material stoichiometry. Compared to the pristine ZTO, the ZTO-ZnO and ZTO-SnO 2 composites have an enhanced PSC performance. The ZTO-SnO 2 composites exhibit better band matching and charge transfer behavior with the perovskite layer than the pristine ZTO and ZTO-ZnO composites. ZTO-SnO 2 ETL-based PSC device displays a maximum efficiency of 15.6 %, while ZTO-ZnO shows a maximum efficiency of 13.1 %, which is more than 10.5 % for the pristine ZTO. The results indicate that Zn 2SnO 4-based composites can be suitable for ETL in PSC device fabrication.