Credit: Martin Künsting / HZB
Researchers from HZB have published their findings on cleaved bulk MoS2 surfaces, paving the way for further understanding of their irreproducible electronic properties. The team utilized X-ray photoelectron spectroscopy to map core-level electron energies and monitor changes in the surface electronic properties.
Molybdenum disulfide (MoS2) is a versatile material with wide-ranging applications including green hydrogen production via photocatalysis. Historically, studies conducted on MoS2 show diverse and irreproducible results for the electronic properties of the material, demonstrating the need for further studies to understand its properties.
The team of researchers at HZB carried out a systemic study at the LowDosePES end-station of the BESSY II light source, utilizing X-ray photoelectron spectroscopy to monitor the changes in the electronic properties after in-situ ultra-high-vacuum cleaving, annealing and exposure to atomic and molecular hydrogen.
The results of the study, published in Advanced Materials Interfaces, highlight two important findings. First, in freshly cleaved surfaces there are sizeable variations and instabilities in electron energies which the researchers believe to be the cause of the irreproducible outcomes. Second, the researchers found that room-temperature atomic hydrogen is highly effective at neutralizing this inhomogeneity and instability thanks to its ability to accept or give away an electron. "We hypothesize that atomic hydrogen helps rearranging sulfur vacancies and excess of sulfur atoms yielding a more ordered structure," Said Dr. Erika Giangrisostomi.
Due to the extensive use of MoS2, the findings of the study could have wide applications in numerous industries including electronics, sensors, and catalysis. The study is a necessary fundamental step toward understanding MoS2 and its applications.