Effect of Erbium Nanoparticles on Optical Properties of Zinc Borotellurite Glass System

Table 4

Indirect optical band gap (𝐸¹_opt), direct optical band gap (𝐸²_opt), and Urbach energy (Δ𝐸) of erbium NPs doped glass samples.

Sample, 𝑦	𝐸^1opt	𝐸^2opt	Δ𝐸 (eV)
0.000	3.280	3.600	0.185
0.005	3.882	4.440	0.265
0.010	3.876	4.390	0.270
0.020	3.870	4.385	0.272
0.030	3.860	4.380	0.273
0.040	3.850	4.370	0.271
0.050	3.840	4.360	0.276