SOFT X-RAY SPECTROSCOPY STUDY of WIDE BAND GAP SEMICONDUCTORS-M2PN3 (M=Mg, Zn) and BP3N6
Date
2020-08-28
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ORCID
Type
Thesis
Degree Level
Masters
Abstract
The research on nitridophosphate materials has gained significant attention in recent years due to the abundance of elements like Mg, Zn, P, and N. The compound semiconductors comprising of these earth-abundant elements are important in terms of manufacturing cost of electronic devices and no detrimental impact on the environment. Here in this thesis, a detailed study of band gap and electronic structure of M2PN3 (M=Mg, Zn) and BP3N6 is presented using synchrotron-based soft X-ray spectroscopy measurements as well as Density Functional Theory (DFT) calculations. The experimental N K-edge X-ray emission spectroscopy (XES) and X-ray absorption spectroscopy (XAS) spectra are used to estimate the band gaps, which are compared with calculations along with the values available in literature. The band gap, which is essential for electronic device applications, is experimentally determined for the first time to be 5.3 ± 0.2 eV, 4.2 ± 0.2 eV, and 5.3 ± 0.2 for Mg2PN3, Zn2PN3, and BP3N6, respectively. The experimental band gaps agree well with the calculated band gaps of 5.4 eV for Mg2PN3, 3.9 eV for Zn2PN3, and 5.8 eV for BP3N6 using the modified Becke-Johnson (mBJ) exchange potential. The states that contribute to the band gap are investigated with the calculated density of states especially with respect to the non-equivalent N sites in the structure. The calculations and the measurements predict that all the three materials studied here in this thesis, have an indirect band gap. The wide band gap of M2PN3 (M=Mg, Zn) and BP3N6 could make it promising for the application in photovoltaic cells, high power RF applications, as well as power electronic devices.
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Keywords
Nitridophosphate, Semiconductor, Wide Band Gap, Nitrides, Density Functional Theory, Synchrotron, Soft X-ray Spectroscopy.
Citation
Degree
Master of Science (M.Sc.)
Department
Electrical and Computer Engineering
Program
Electrical Engineering