BiI3 is a non-toxic solar absorber material that is well matched for tandem-junction photovoltaic devices. We synthesized single-crystal samples via chemical vapor transport and physical vapor transport in evacuated ampoules to yield BiI3 flakes with mm2-to-cm2 terraces and explored the effect of various oxidizing atmospheres. Oxidation methods included immersion in degassed water, ultraviolet illumination under an oxygen ambient, and a sequence of ultraviolet illumination under oxygen and subsequent water immersion. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) quantified the chemical changes as a function of oxidative treatments. Spectra reveal that water immersion of BiI3 yields BiOI(102) reflections that are thicker than photoelectron probe depths. Ultraviolet illumination under an oxygen ambient forms bismuth oxide that subsequently converts to BiOI(001) upon water immersion. We discuss the implications of these surface chemical transformations for the long-term atmospheric stability of BiI3-containing solar energy conversion devices.

Creator

• Stoflet, Roy

Contributors

• Musacchio, Patricia Z.
• Grimm, Ronald
• Rao, Pratap M.

Degree

• MS

Unit

• Chemistry & Biochemistry

Publisher

• Worcester Polytechnic Institute

Identifier

• etd-64726

Advisor

• Grimm, Ronald

Orcid

• https://orcid.org/0000-0001-8336-7163

Committee

• Rao, Pratap M.
• Musacchio, Patricia Z.

Defense date

• 2022-04-21

Year

• 2022

Date created

• 2022-04-27

Resource type

• Thesis

Rights statement

• In Copyright

License

• Creative Commons BY-NC Attribution-NonCommercial 4.0 International