ZnO nanorod arrays with different densities in hybrid photovoltaic devices: Fabrication and the density effect on performance

► Hybrid solar cells with different-density ZnO nanorod arrays (NRAs) were prepared. ► The interspaces of low-density ZnO NRAs facilitate polymer to infiltrate completely. ► Low-density ZnO NRAs' solar cell shows a great improvement in the device performance.