Cu2O and CuO are direct and indirect band gap materials respectively. We deposited a film that shows the Raman signatures of both CuO and Cu2O, what will be their band gap, direct or indirect?
Dear Muhammad,
Is it possible to estimate the percentage of CuO and Cu2O from your measurements?
Most likely, dominant component will be responsible for the formation of absorption edge, and, as a consequence, for type of interband transitions (direct or indirect).
In addition, there is equation which allows to estimate the band gap for multicomponent systems. You can find it in attached article.
Regards,
Yulia
It is so as the particle size decreases the indirect gap material tend to direct gap material with increase in the band gap. So, if the material is composed of nano particles it will tend to be direct bangap not only because of the presence of direct bandgap component but also because of the small grain size.
Otherwise i agree with the answer above. According to the mixing ratio, the material will vary from pure indirect gap to pure direct bandgap.
Best wishes
Hello Muhamed,
it is unclear, what your notation "mixture" means. If mixture means only a mixing that you have a powder, then the properties of the components are conserved. You can estimate the percentage from the intensity ratio.
If the components are fitted to a solid -may be weak molten- then you have grain boundaries between the different components but the solid behaves like a powder.
If you grow a crystal (solid solution), then the properties of the mixing crystal depend on the concentration ratio of the components. I expect the observation from a direct to an indirect semiconductor as a function of the composition.
An example: Ga1-xPx is a direct semiconductor for x0,5 (the center must not be ever x = 0,5). But you cannot have both simultaneously.
Therefrom I conclude you have indeed a misture of 2 components and can the ratio determine after a calibration.
With Regard
R. Mitdank
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Semiconductor