Structural and Optical Properties of ZnWO₄:Er³⁺ Crystals

Figure 3

SEM images of different Er³⁺-doped ZnWO₄ samples: (a) 0%, (b) 2%, (c) 4%, (d) 6%, (e) 8%, and (f) 15%.

(a)

(b)

(c)

(d)

(e)

(f)