Mechanistic Investigation of Molybdenum Disulfide Defect Photoluminescence Quenching by Adsorbed Metallophthalocyanines
| Autor: | Maria K. Y. Chan, Shawn Irgen-Gioro, Vinod K. Sangwan, Samuel H. Amsterdam, Qunfei Zhou, Akshay A. Murthy, Pierre Darancet, Tobin J. Marks, Luqing Wang, Nathaniel P. Stern, Emily A. Weiss, Teodor K. Stanev, Mark C. Hersam, Suyog Padgaonkar, Vinayak P. Dravid |
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| Rok vydání: | 2021 |
| Předmět: |
Photoluminescence
Quenching (fluorescence) business.industry Fermi level General Chemistry Photochemistry Biochemistry Catalysis chemistry.chemical_compound symbols.namesake Colloid and Surface Chemistry Semiconductor chemistry Monolayer Phthalocyanine symbols Density functional theory business Molybdenum disulfide |
| Zdroj: | Journal of the American Chemical Society. 143(41) |
| ISSN: | 1520-5126 |
| Popis: | Lattice defects play an important role in determining the optical and electrical properties of monolayer semiconductors such as MoS2. Although the structures of various defects in monolayer MoS2 are well studied, little is known about the nature of the fluorescent defect species and their interaction with molecular adsorbates. In this study, the quenching of the low-temperature defect photoluminescence (PL) in MoS2 is investigated following the deposition of metallophthalocyanines (MPcs). The quenching is found to significantly depend on the identity of the phthalocyanine metal, with the quenching efficiency decreasing in the order CoPc > CuPc > ZnPc, and almost no quenching by metal-free H2Pc is observed. Time-correlated single photon counting (TCSPC) measurements corroborate the observed trend, indicating a decrease in the defect PL lifetime upon MPc adsorption, and the gate voltage-dependent PL reveals the suppression of the defect emission even at large Fermi level shifts. Density functional theory modeling argues that the MPc complexes stabilize dark negatively charged defects over luminescent neutral defects through an electrostatic local gating effect. These results demonstrate the control of defect-based excited-state decay pathways via molecular electronic structure tuning, which has broad implications for the design of mixed-dimensional optoelectronic devices. |
| Databáze: | OpenAIRE |
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