Investigating the Material Properties of Nanostructured Sulvanite-Type Compounds Through Computational Methods

Authors

Roberto B. Prado-Rivera, Florida International UniversityFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Mechanical Engineering

First Advisor's Name

Daniela Radu

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

Cheng-Yu Lai

Second Advisor's Committee Title

Committee Member

Third Advisor's Name

Darryl Dickerson

Third Advisor's Committee Title

Committee Member

Fourth Advisor's Name

Alexander Mebel

Fourth Advisor's Committee Title

Committee Member

Fifth Advisor's Name

Yuanxi Wang

Fifth Advisor's Committee Title

Committee Member

Keywords

DFT, sulvanite, nanostructured, Cu3MX4, RbCu2MX4, optoelectronics, chalcogenides, nanomaterials, semiconductors, photovoltaics

Date of Defense

6-27-2023

Abstract

Searching for new photovoltaic materials involves finding nontoxic materials, inexpensive to produce, composed of Earth-abundant elements, scalable fabrication, and exhibit good performance. Silicon has dominated the solar cell market but is expensive and requires thick layers to achieve high performance. Chalcogenide thin films such as CdTe, CuIn_1-xGa_xSe₂, and Cu₂ZnSn(S/Se)₄ demonstrate promise but are plagued with a variety of problems such as toxicity-associated health risks, supply issues, and film quality. Thus, we must look towards newer materials to circumvent these issues.

In this work, the novel nanostructured ternary copper chalcogenides Cu₃MX₄ (M=V, Nb, Ta; X=S, Se) in novel nanostructured forms were investigated for their potentials in photovoltaics via first-principles calculations. We first study the phase stability of nanostructured Cu₃MX₄ surfaces through thermodynamic considerations. It was found that there is a strong preference for surfaces with dangling chalcogen bonds and underlying Cu-M layer that simultaneously reproduces critical features from the parent bulk structure. Next, the electronic structure and optical absorption spectra of nanostructured Cu₃MX₄ were simulated utilizing the results of the phase stability study, revealing the influence of the phases on the conductive behavior, high absorption with minor anisotropy, and band gaps suitable for photovoltaics. Finally, the compounds RbCu₂MX₄ were considered the next “step” in converting bulk Cu₃MX₄ into layered form. Electronic structure calculations demonstrated that RbCu₂MX₄ has similar semiconducting behavior to Cu₃MX_4­, showing that Rb acts to intercalate Cu₃MX₄ so that RbCu₂MX₄ may be considered as a sulvanite-derived compound. We also determine the nonlinear optical behavior of Cu₃MX₄ and RbCu₂MX₄ for the first time by calculating the second-order susceptibility. Results indicate appreciable nonlinear optical response and an enhancement in the susceptibility for RbCu₂MX₄,which shows promise for nonlinear optical applications such as frequency doubling.

Identifier

FIDC011134

ORCID

0000-0002-3376-6673

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.

Recommended Citation

Prado-Rivera, Roberto B., "Investigating the Material Properties of Nanostructured Sulvanite-Type Compounds Through Computational Methods" (2023). FIU Electronic Theses and Dissertations. 5441.
https://digitalcommons.fiu.edu/etd/5441