“…Moreover, SnO 2 exhibits a high transparency in the visible range and a strong reflectivity in the NIR region [16]. In addition to the TCO properties, SnO 2 can be doped with trivalent rare earth elements (RE) such as Yb, Er, Eu, Ce, Sm and Nd [17][18][19][20][21], which generates novel properties without affecting transparency or other key properties thanks to the photoluminescence properties of these ions.…”