Table 10 Band gap energy analysis.

1

Co-doped SnO₂

Sol–Gel

2.85

Slight band gap narrowing with cobalt doping

⁴⁴

2

SnO₂

Sol–gel

3.26

Band gap narrowing due to particle size effects

⁴⁵

3

SnO₂ thin-film (FTO)

Chemical deposition

3.65

Higher band gap due to fluorine and indium doping

⁴⁶

4

SnO₂

Hydrothermal

3.87

Higher band gap enhances gas sensing capabilities

⁴⁷

5

Al-doped SnO₂

Precipitation

3.15

Band gap increases slightly with Zn doping

⁴⁸

6

SnO₂ and ZnO thin films

Thin film deposition

3

SnO₂ shows higher band gap with improved crystallinity

⁴⁹

7

SnO₂ nanostructures

Sol–Gel

3.36

Band gap decreases with increasing temperature

⁵⁰

8

SnO₂ and MoS₂

Hydrothermal

2.68

MoS₂ inclusion leads to band gap narrowing

⁵¹