تقرير
Localized Gradual Photomediated Brightness and Lifetime Increase of Superacid Treated Monolayer MoS$_2$
| العنوان: | Localized Gradual Photomediated Brightness and Lifetime Increase of Superacid Treated Monolayer MoS$_2$ |
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| المؤلفون: | Tyson, Kurt H., Godfrey, James R., Fraser, James M., Knobel, Robert G. |
| سنة النشر: | 2024 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Materials Science |
| الوصف: | Monolayer semiconducting transition metal dichalcogenides (S-TMDs) have been extensively studied as materials for next-generation optoelectronic devices due to their direct band gap and high exciton binding energy at room temperature. Under a superacid treatment of bis(trifluoromethane)sulfonimide (TFSI), sulfur-based TMDs such as MoS$_2$ can emit strong photoluminescence (PL) with photoluminescence quantum yield (PLQY) approaching unity. However, the magnitude of PL enhancement varies by more than two orders of magnitude in published reports. A major culprit behind the discrepancy is sulfur-based TMD's sensitivity to above band-gap photostimulation. Here, we present a detailed study of how TFSI-treated MoS$_2$ reacts to photostimulation with increasing PL occurring hours after constant or pulsed laser exposure. The PL of TFSI-treated MoS$_2$ is enhanced up to 74 times its initial intensity after 5 hours of continuous exposure to 532nm laser light. Photostimulation also enhances the PL of untreated MoS$_2$ but with a much smaller enhancement. Caution should be taken when probing MoS$_2$ PL spectra as above-bandgap light can alter the resulting intensity and peak wavelength of the emission over time. The presence of air is verified to play a key role in the photostimulated enhancement effect. Additionally, the rise of PL intensity is mirrored by an increase in measured carrier lifetime of up to ~400ps consistent with the suppression of non-radiative pathways. This work demonstrates why variations in PL intensity are observed across samples and provides an understanding of the changes in carrier lifetimes to better engineer next-generation optoelectronic devices. Comment: Main document: 15 pages, 4 figures. Supplemental document: 12 pages, 7 figures |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2401.06231 |
| رقم الأكسشن: | edsarx.2401.06231 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |