Λεπτομέρειες βιβλιογραφικής εγγραφής
| Τίτλος: |
Distinct absolute bandgap deformation potentials of direct and indirect gaps in bilayer WSe2. |
| Συγγραφείς: |
Prasad, Indrajeet Dhananjay1, Shit, Sumitra1, Waheed, Yunus1, Surendran, Jithin Thoppil1, Watanabe, Kenji2, Taniguchi, Takashi3, Kumar, Santosh1 skumar@iitgoa.ac.in |
| Πηγή: |
Applied Physics Letters. 6/22/2026, Vol. 128 Issue 25, p1-7. 7p. |
| Θεματικοί όροι: |
*Bilayers (Solid state physics), *Transition metal chalcogenides, *Raman spectroscopy, *Photoluminescence, *Flexible electronics |
| Περίληψη: |
Bilayer (BL) transition metal dichalcogenides exhibit rich optoelectronic phenomena, including strong strain-induced bandgap tunability and creation of strain-induced spectrally isolated quantum-light emitters. However, two important governing parameters of strain tunability—absolute bandgap deformation potentials (DPs) and mode Grüneisen parameters—remain largely unexplored. Here, we focus on the K c and Q c conduction-band valleys and the K v valence-band valley of BL WSe 2 , and create localized biaxial strain using dielectric nanoparticle stressors. By combining spatially resolved Raman spectroscopy at room temperature and photoluminescence spectroscopy at low (4–130 K) and room temperatures with a theoretical model, we extract DPs of −6.04 eV for the Q c – K v indirect bandgap and −8.45 eV for the K c – K v direct bandgap. These results indicate that approximately 0.9 % biaxial tensile strain is sufficient to drive an indirect-to-direct bandgap transition in BL WSe 2 , in agreement with previous reports. We also measure a Grüneisen parameter of 1.55 for the E 2 g mode. Notably, a localized strain of only ∼ 0.4 % renders BL WSe 2 optically as bright as an unstrained monolayer. This work paves the way for advances in flexible electronics, sensors, optoelectronics, and quantum-photonic devices through precise strain engineering of BL WSe 2 . [ABSTRACT FROM AUTHOR] |
| Βάση Δεδομένων: |
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