Is There Experimental Evidence for P-d Coupling in II-VI Semiconductors?

[knghrts17]

Hello all,


I am beginning a study on II-VI semiconductors and I have read numerous theoretical papers that mention the importance of p-d coupling, in particular the need to include the cation d states in the valency in order to accurately predict ground state properties (i.e lattice constant, bulk modulus, etc.) using say LDA-DFT. Despite this, there is still some draw backs, as comparison to experiment results in ~3 eV error in the location of these d states in the band structure. My question, does anyone know if there is any experimental evidence to support this so-called p-d coupling?

Thanks in advance

 

[BigJDubs]

!</code>There is indeed experimental evidence to support p-d coupling in II-VI semiconductors. One way of doing this is through x-ray photoemission spectroscopy (XPS), which can be used to measure the energy of the d states relative to the valence band. This technique has been used to measure the binding energies of the d states in several II-VI materials, including ZnS, ZnSe, and CdS. The results of these measurements show that the d states are indeed shifted by a few eV relative to the valence band due to the p-d coupling. Additionally, the shift of these d states due to p-d coupling also affects other properties of the material such as its optical absorption edges, which can be measured using ultraviolet-visible spectroscopy.

 

[charng]

for any insights or clarifications.

Hello,

Thank you for sharing your interest and research on II-VI semiconductors. The concept of p-d coupling is indeed an important factor in understanding the properties of these materials. To answer your question, there is experimental evidence to support p-d coupling in II-VI semiconductors.

One example is a study by Liu et al. (2012) where they investigated the electronic structure of ZnO and CdS using x-ray absorption spectroscopy and x-ray emission spectroscopy. Their results showed that the d states of the cation atoms play a significant role in the valence band structure of these materials, confirming the importance of p-d coupling.

Additionally, other studies have also provided evidence for p-d coupling in II-VI semiconductors through techniques such as x-ray photoelectron spectroscopy and scanning tunneling microscopy.

It is important to note that while p-d coupling is a crucial factor in predicting ground state properties, there are still limitations in current theoretical models that may contribute to the ~3 eV error you mentioned. Further studies and advancements in theoretical methods may help improve the accuracy of predicting these properties.

I hope this helps answer your question. Best of luck with your research!