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   https://doi.org/10.1021/acs.jpcc.2c05661  

   Tang, Xueting; Khurana, Mohit; Rossi, Daniel; Luo, Lanyin; Akimov, Alexey V.; Son, Dong Hee (November 2022, The Journal of Physical Chemistry C)
2. Trion-Species-Resolved Quantum Beats in MoSe ₂

   https://doi.org/10.1021/acsnano.7b06444  

   Shepard, Gabriella D.; Ardelean, Jenny V.; Ajayi, Obafunso A.; Rhodes, Daniel; Zhu, Xiaoyang; Hone, James C.; Strauf, Stefan (September 2017, ACS Nano)
3. Quantum-Cutting Ytterbium-Doped CsPb(Cl _1–x Br _x ) ₃ Perovskite Thin Films with Photoluminescence Quantum Yields over 190%

   https://doi.org/10.1021/acsenergylett.8b01528  

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4. Polysalt ligands achieve higher quantum yield and improved colloidal stability for CsPbBr ₃ quantum dots

   https://doi.org/10.1039/d1nr04753a  

   Wang, Sisi; Du, Liang; Donmez, Selin; Xin, Yan; Mattoussi, Hedi (October 2021, Nanoscale)

   Colloidal lead halide perovskite quantum dots (PQDs) are relatively new semiconductor nanocrystals with great potential for use in optoelectronic applications. They also present a set of new scientifically challenging fundamental problems to investigate and understand. One of them is to address the rather poor colloidal and structural stability of these materials under solution phase processing and/or transfer between solvents. In this contribution, we detail the synthesis of a new family of multi-coordinating, bromide-based polysalt ligands and test their ability to stabilize CsPbBr 3 nanocrystals in polar solutions. The ligands present multiple salt groups involving quaternary cations, namely ammonium and imidazolium as anchors for coordination onto PQD surfaces, along with several alkyl chains with varying chain length to promote solubilization in various conditions. The ligands provide a few key benefits including the ability to repair damaged surface sites, allow rapid ligand exchange and phase transfer, and preserve the crystalline structure and morphology of the nanocrystals. The polysalt-coated PQDs exhibit near unity PLQY and significantly enhanced colloidal stability in ethanol and methanol. 

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5. Imaging quantum spin Hall edges in monolayer WTe ₂

   https://doi.org/10.1126/sciadv.aat8799  

   Shi, Yanmeng; Kahn, Joshua; Niu, Ben; Fei, Zaiyao; Sun, Bosong; Cai, Xinghan; Francisco, Brian A.; Wu, Di; Shen, Zhi-Xun; Xu, Xiaodong; et al (February 2019, Science Advances)

   A two-dimensional (2D) topological insulator exhibits the quantum spin Hall (QSH) effect, in which topologically protected conducting channels exist at the sample edges. Experimental signatures of the QSH effect have recently been reported in an atomically thin material, monolayer WTe 2 . Here, we directly image the local conductivity of monolayer WTe 2 using microwave impedance microscopy, establishing beyond doubt that conduction is indeed strongly localized to the physical edges at temperatures up to 77 K and above. The edge conductivity shows no gap as a function of gate voltage, and is suppressed by magnetic field as expected. We observe additional conducting features which can be explained by edge states following boundaries between topologically trivial and nontrivial regions. These observations will be critical for interpreting and improving the properties of devices incorporating WTe 2 . Meanwhile, they reveal the robustness of the QSH channels and the potential to engineer them in the monolayer material platform. 

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