fig2
![Recent advancement of solid oxide fuel cells towards semiconductor membrane fuel cells](https://image.oaes.cc/b769612f-5790-42fe-aa9a-c5948257ae59/em4054.fig.2.jpg)
Figure 2. (A) Yttria-stabilized zirconia (YSZ) is a cubic crystal structure of zirconium dioxide with the addition of yttrium oxide. (B) Ceria has a fluorite structure and is mainly partially replaced by lower-valence Mn+ (Gd3+ or Sm3+) to create gadolinium/samarium-doped ceria (GDC)[36].