2025/03/29 by Olkowska-Pucko, Katarzyna, Woźniak, Tomasz, Blundo, Elena +24 · 1 citation
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
paper · doi:10.48550/arxiv.2503.23071
Monolayers (MLs) of semiconducting transition metal dichalcogenides (S-TMDs) emit light very efficiently and display rich spin-valley physics, with gyromagnetic (g-) factors of about -4. Here, we investigate how these properties can be tailored by alloying. Magneto-optical spectroscopy is used to reveal the peculiar properties of excitonic complexes in MoxW1-xSe2 MLs with different Mo and W concentrations. We show that the alloys feature extremely high g-factors for neutral excitons, that change gradually with the composition up to reaching values of the order of -10 for x ≈ 0.2. First-principles calculations corroborate the experimental findings and provide evidence that alloying in S-TMDs results in a non-trivial band structure engineering, being at the origin of the high g-factors. The theoretical framework also suggests a higher strain sensitivity of the alloys, making them promising candidates for tailor-made optoelectronic devices.