Strain effect on the intraband absorption coefficient for spherical CdSe/CdS/ZnSe core–shell–shell quantum dots

2022 ◽  
Vol 141 ◽  
pp. 106400
K.A. Rodríguez-Magdaleno ◽  
R. Pérez-Álvarez ◽  
F. Ungan ◽  
J.C. Martínez-Orozco
2016 ◽  
Vol 97 ◽  
pp. 489-494 ◽  
Negar Gheshlaghi ◽  
Hadi Sedaghat Pisheh ◽  
M. Rezaul Karim ◽  
Derya Malkoc ◽  
Hilmi Ünlü

2019 ◽  
Aurelio A. Rossinelli ◽  
Henar Rojo ◽  
Aniket S. Mule ◽  
Marianne Aellen ◽  
Ario Cocina ◽  

<div>Colloidal semiconductor nanoplatelets exhibit exceptionally narrow photoluminescence spectra. This occurs because samples can be synthesized in which all nanoplatelets share the same atomic-scale thickness. As this dimension sets the emission wavelength, inhomogeneous linewidth broadening due to size variation, which is always present in samples of quasi-spherical nanocrystals (quantum dots), is essentially eliminated. Nanoplatelets thus offer improved, spectrally pure emitters for various applications. Unfortunately, due to their non-equilibrium shape, nanoplatelets also suffer from low photo-, chemical, and thermal stability, which limits their use. Moreover, their poor stability hampers the development of efficient synthesis protocols for adding high-quality protective inorganic shells, which are well known to improve the performance of quantum dots. <br></div><div>Herein, we report a general synthesis approach to highly emissive and stable core/shell nanoplatelets with various shell compositions, including CdSe/ZnS, CdSe/CdS/ZnS, CdSe/Cd<sub>x</sub>Zn<sub>1–x</sub>S, and CdSe/ZnSe. Motivated by previous work on quantum dots, we find that slow, high-temperature growth of shells containing a compositional gradient reduces strain-induced crystal defects and minimizes the emission linewidth while maintaining good surface passivation and nanocrystal uniformity. Indeed, our best core/shell nanoplatelets (CdSe/Cd<sub>x</sub>Zn<sub>1–x</sub>S) show photoluminescence quantum yields of 90% with linewidths as low as 56 meV (19.5 nm at 655 nm). To confirm the high quality of our different core/shell nanoplatelets for a specific application, we demonstrate their use as gain media in low-threshold ring lasers. More generally, the ability of our synthesis protocol to engineer high-quality shells can help further improve nanoplatelets for optoelectronic devices.</div>

2019 ◽  
Vol 29 (46) ◽  
pp. 1904501 ◽  
Chao Wang ◽  
David Barba ◽  
Gurpreet S. Selopal ◽  
Haiguang Zhao ◽  
Jiabin Liu ◽  

Lishuang Wang ◽  
Ying Lv ◽  
Jie Lin ◽  
Jialong Zhao ◽  
Xingyuan Liu ◽  

For quantum dots light-emitting diodes (QLEDs), typical colloidal quantum dots (QDs) are usually composed of a core/shell heterostructure which is covered with organic ligands as surface passivated materials to confine...

Nanoscale ◽  
2021 ◽  
Tuhin Shuvra Basu ◽  
Simon Diesch ◽  
Ryoma Hayakawa ◽  
Yutaka Wakayama ◽  
Elke Scheer

We examined the modified electronic structure and single-carrier transport of individual hybrid core–shell metal–semiconductor Au-ZnS quantum dots using a scanning tunnelling microscope.

2021 ◽  
Vol 548 ◽  
pp. 149252
Sanchaya Pandit ◽  
Sundar Kunwar ◽  
Rakesh Kulkarni ◽  
Rutuja Mandavka ◽  
Shusen Lin ◽  

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