Cubic silicon carbide/zinc oxide heterostructure fuel cells
Yueming Xing, Enyi Hu, Faze Wang, Naveed Muhammad, Baoyuan Wang, Jun Wang, Ammara Maryam, Muhammad Naveed Rasheed, M. Asghar, Xia Chen, Sining Yun, Bin Zhu
Abstract
Multifunctional semiconductor cubic silicon carbide (3C-SiC) is employed for fuel cell electrolyte, which has never been used before. n-type 3C-SiC can be individually employed as the electrolyte in fuel cells, but delivers insufficient open circuit voltage and minuscule current density due to its electronic dominant property. By introducing n-type ZnO to form an n–n 3C-SiC/ZnO heterostructure, significant enhancements in the ionic conductivity of 0.12 S/cm and fuel cell performance of 270 mW cm−2 are achieved at 550 °C. It is found that the energy band bending and build-in electric field of the heterostructure play the pivotal role in the ionic transport and suppressing the electronic conduction of 3C-SiC, leading to a markable material ionic property and fuel cell performance. These findings suggest that 3C-SiC can be tuned to ionic conducting electrolyte for fuel cell applications through the heterostructure approach and energy band alignment methodology.