Figure 2From: Improving scattering layer through mixture of nanoporous spheres and nanoparticles in ZnO-based dye-sensitized solar cellsPlan-view and cross-sectional SEM images of the ZnO bilayer electrodes. The weight ratios of nanoparticle (NP) to nanoporous sphere (NS) for the top layers are (a) 10:0, (b) 7:3, (c) 5:5, (d) 3:7, and (e) 0:10, respectively. Blue labeled boxes are higher magnification for the bilayer interface.Back to article page