Article
Chemistry, Multidisciplinary
Hongyu Yang, Lei Zhang, Wenbin Xiang, Changgui Lu, Yiping Cui, Jiayu Zhang
Summary: In this study, room-temperature exciton-polariton Bose-Einstein condensation was achieved and the realization of polariton laser was confirmed. Colloidal nanoplatelets show great prospects in low-cost, high-performance polariton devices and coherent light sources.
Article
Chemistry, Multidisciplinary
Wenbin Xiang, Baohua Zhu, Chunzheng Bai, Bing Gu, Changgui Lv, Jiayu Zhang
Summary: In this study, CdSe-CdS core-shell nanoplatelets were synthesized and the third-order nonlinear optical properties related to shell thickness were measured. The study found that the imaginary part of the third-order nonlinear susceptibility increased monotonically with the growth of shell thickness, while the real part showed a non-monotonic change. The trends were further explained by analyzing the optical properties and understanding the variations in defect distribution, exciton binding energy, and quantum confinement effects. The results highlighted the importance of proper shell passivation in enhancing the luminescent performance and third-order nonlinearity of the nanoplatelets.
Article
Chemistry, Physical
Nina N. Kurus, Alexander G. Milekhin, Roman Sklyar, Bedil M. Saidzhonov, Roman B. Vasiliev, Sergei Adichtchev, Nikolai Surovtsev, Alexander Latyshev, Dietrich R. T. Zahn
Summary: The phonon spectra of core/shell CdSe/CdS nanoplatelets with different shell thicknesses were studied, revealing frequency shifts of optical modes as the shell thickness increases, which can be explained in terms of the stress state in the core and shell, as well as the influence of phonon confinement.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Dongdong Chen, Hairui Lei, Chenqi Zhu, Xing Chen, He Tian, Wei Fang, Haiyan Qin, Xiaogang Peng
Summary: In this study, pre-synthesized CdSe/CdS core/shell quantum dots were fused together in solution to form CdS nanoplatelets with multiple embedded CdSe quantum dots. The resulting structure exhibited homogeneous-free optical properties and demonstrated unique and complex excitonic characteristics.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Yonglei Sun, Hua Zhu, Na Jin, Ou Chen, Jing Zhao
Summary: Lifetime blinking, a phenomenon of fluctuations in the fluorescence lifetime of a single quantum dot over time while its fluorescence intensity remains relatively stable, has been reported in a few QD systems. In this study, statistical methods demonstrate that compact CdSe/CdS core/shell QDs also exhibit short-lived lifetime blinking events, possibly due to the activation of efficient nonradiative processes leading to intensity blinking.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Grigor A. Mantashian, Paytsar A. Mantashyan, Hayk A. Sarkisyan, Eduard M. Kazaryan, Gabriel Bester, Sotirios Baskoutas, David B. Hayrapetyan
Summary: This study theoretically investigates exciton-related Raman scattering, interband absorption, and photoluminescence in colloidal CdSe/CdS core/shell quantum dots ensemble using numerical discretization method within the effective-mass approximation. The interband optical absorption and photoluminescence spectra for CdSe/CdS quantum dots are revealed, taking into account the size dispersion of the ensemble. Numerical calculation of the differential cross section for exciton-related Stokes-Raman scattering in CdSe/CdS quantum dots ensemble with different mean sizes is presented.
Article
Optics
I. D. Laktaev, B. M. Saidzhonov, R. B. Vasiliev, A. M. Smirnov, O. V. Butov
Summary: The photoluminescence features of a light-hole - electron exciton transition in CdSe/CdS nanoplatelets colloidal solution under resonant two-photon excitation were investigated. The powerlaw dependence of the photoluminescence intensity on the excitation laser femtosecond pulses intensity was discovered to be related to biexciton radiation. In addition, the conditions for the photoluminescence growth and quenching were determined based on the concentration and pump intensity.
JOURNAL OF LUMINESCENCE
(2022)
Article
Chemistry, Multidisciplinary
Carmelita Roda, Alessio Di Giacomo, Lucia Camila Tasende Rodriguez, M. Chandra Sekhar, Jari Leemans, Zeger Hens, Pieter Geiregat, Iwan Moreels
Summary: We synthesized CdSe/CdS nanoplatelets with 3.5 monolayers, which exhibit saturated blue emission and high photoluminescence quantum efficiency (PL QE) up to 55%. Compared to core-only nanoplatelets, the PL intensity decays exponentially due to suppressed deep trapping and delayed emission. Both core-only and core/crown nanoplatelets show biexciton-mediated optical gain between 470 and 510 nm, with higher gain coefficients in crowned nanoplatelets. However, the gain lifetimes are limited to 40 ps due to residual ultrafast trapping and higher exciton densities at threshold. These findings provide guidelines for optimizing CdSe nanoplatelets for lighting and light-amplification applications.
Article
Chemistry, Physical
Jiakuan Zhang, Chuyue Li, Jiongzhao Li, Xiaogang Peng
Summary: Size- and shape-controlled CdSe/ZnSe core/shell and CdSe/ZnSe/ZnS core/shell/shell nanocrystals with zinc-blende structure are synthesized. The ligand strain between the inorganic crystal surface and organic ligands plays a key role in ZnSe epitaxy. The lattice strain between the CdSe and ZnSe affects the photoluminescence of CdSe/ZnSe/ZnS core/shell/shell QDs.
CHEMISTRY OF MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Matteo Barelli, Cynthia Vidal, Sergio Fiorito, Alina Myslovska, Dimitrie Cielecki, Vincenzo Aglieri, Iwan Moreels, Riccardo Sapienza, Francesco Di Stasio
Summary: This study demonstrates the controlled placement of colloidal semiconductor nanocrystals onto planar surfaces by patterning nanohole arrays in a PMMA thin film and trapping the nanocrystals into the holes. The resulting arrays contain hundreds of single-photon emitters, providing a feasible, fast, and practical method for the fabrication of nanodevices based on colloidal semiconductor nanocrystals, such as single-photon-emitting LEDs.
Article
Chemistry, Multidisciplinary
Volodymyr Dzhagan, Nazar Mazur, Olga Kapush, Oleksandr Selyshchev, Anatolii Karnaukhov, Oleg A. Yeshchenko, Mykola I. Danylenko, Volodymyr Yukhymchuk, Dietrich R. T. Zahn
Summary: This study investigates the influence of the parameters of the shell and interface in semiconductor core/shell nanocrystals (NCs) on their optical properties and charge transfer, using Raman spectroscopy. The results show that the use of thioglycolic acid (TGA) during the synthesis leads to the formation of a CdS shell around the CdTe core in the NCs. The optical absorption and photoluminescence bands of these NCs are determined by the CdTe core, while the far-infrared absorption and resonant Raman scattering spectra are dominated by the vibrations related to the shell.
Article
Chemistry, Multidisciplinary
Andrew B. Pun, Aniket S. Mule, Jacob T. Held, David J. Norris
Summary: The research team successfully grew thin CdS shells on CdSe MSNC cores via high-temperature synthesis, dramatically improving the emissive properties of the MSNCs. Thicker CdS shells result in decreased performance, but CdxZn1-xS alloyed shells maintain efficient and narrow emission lines.
Article
Chemistry, Multidisciplinary
Sergii Morozov, Stefano Vezzoli, Alina Myslovska, Alessio Di Giacomo, N. Asger Mortensen, Iwan Moreels, Riccardo Sapienza
Summary: Giant shell CdSe/CdS quantum dots exhibit high brightness and flexibility, with near-unity quantum yield and suppressed blinking. However, their single photon purity is reduced due to efficient multiexcitonic emission. In this study, we observed a significant blueshift in the photoluminescence biexciton spectrum of pure-phase wurtzite quantum dots. By using spectral filtering, we achieved a 2.3 times reduction in biexciton quantum yield while preserving 60% of the exciton single photon emission, leading to an improvement in purity from g2(0)=0.07±0.01 to g2(0)=0.03±0.01. Furthermore, at higher pump fluence, the spectral purification was even more effective, resulting in up to a 6.6 times reduction in g2(0) by suppressing higher order excitons and shell states with larger blueshifts.
Article
Materials Science, Multidisciplinary
Claudia Gollner, Rokas Jutas, Dominik Kreil, Dmitry N. Dirin, Simon C. Boehme, Andrius Baltuska, Maksym Kovalenko, Audrius Pugzlys
Summary: In this work, an all-optical femtosecond electro-absorption switch is presented, utilizing colloidal quantum dots, capable of high extinction contrast and transmission changes. The absence of physical artifacts allows for a simple numerical model to explain the electric field-induced electro-absorption response.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
A. Allemand, F. Kulzer, B. Mahler, C. Dujardin, J. Houel
Summary: CdS(1.3 nm)/CdSe(1.7 nm)/CdS(3.4 nm) spherical quantum wells (SQWs) with a diameter of 13 nm were synthesized, and photon antibunching from their emission was observed for the first time, confirming them as single-photon sources. The study showed that antibunching persists even at high excitation intensities and is associated with blue-shifted emission.
Article
Physics, Applied
Baohua Zhu, Fangfang Wang, Kun Zhang, Jiayu Zhang, Yuzong Gu
APPLIED PHYSICS EXPRESS
(2016)
Article
Physics, Applied
Baohua Zhu, Fangfang Wang, Yawan Cao, Chong Wang, Ji Wang, Yuzong Gu
APPLIED PHYSICS LETTERS
(2016)
Article
Materials Science, Multidisciplinary
Yawan Cao, Chong Wang, Baohua Zhu, Yuzong Gu
Article
Optics
Baohua Zhu, Fangfang Wang, Chen Liao, Huichao Zhang, Jiayu Zhang, Yiping Cui, Yonghong Ye, Yuzong Gu
Article
Optics
Baohua Zhu, Fangfang Wang, Guixia Wang, Yuzong Gu
PHOTONICS RESEARCH
(2018)
Article
Materials Science, Multidisciplinary
Zhihao Zhang, Baohua Zhu, Peng Li, Pengchao Li, Guixia Wang, Yuzong Gu
Article
Chemistry, Multidisciplinary
Pengchao Li, Baohua Zhu, Peng Li, Zhihao Zhang, Luyao Li, Yuzong Gu
Article
Optics
Yu Hao, Liwei Wang, Baohua Zhu, Yimin Zhang, Yuzong Gu
Summary: In this study, the NLO properties of reduced graphene oxide (rGO) were regulated using a functionalizing strategy with quantum dots (QDs) of gold nanospheres and Au@CdS core-shells. The saturation absorption of rGO weakened with the addition of gold nanospheres, switching to reverse saturation absorption with Au@CdS core-shells. The strength of reverse saturation absorption was tunable with the size of Au@CdS core-shells, while the nonlinear susceptibility was enhanced when combined with Au@CdS core-shells compared to complex gold. The regulation effect was explained by proposing a charge transfer mechanism.
Article
Physics, Applied
Xue Yuan, Fangfang Wang, Yuning Liang, Baohua Zhu, Yuzong Gu
Summary: In this study, Mn-doped semiconductor CdS nanoparticles (RGO/CdS:Mn) were synthesized and applied to modify reduced graphene oxide (RGO) to improve its nonlinear optical properties. The results showed that RGO/CdS:Mn had significantly enhanced nonlinear susceptibility and saturation absorption compared to RGO alone. The improved optical nonlinearity of RGO/CdS:Mn was attributed to charge transfer and trapping effect caused by Mn doping. These findings lay a foundation for the application of RGO/CdS:Mn in photonic devices.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Shihao Chen, Baohua Zhu, Tinglun Xing, Jiejuan Yang, Yuzong Gu
Summary: The composite of graphene and semiconductor nanoparticles shows potential as novel nonlinear optical materials. In this study, composites of reduced graphene oxide (RGO) and SnO2 nanoparticles were synthesized and characterized. The composites exhibited saturable absorption and positive nonlinear refraction properties, with the enhancement tunable by the mass ratio of SnO2 to RGO. The results suggest that the third-order optical nonlinearities of such composites can be controlled for specific applications by adjusting the semiconductor to graphene mass ratio.
MATERIALS RESEARCH EXPRESS
(2022)
Article
Physics, Applied
Siyi Xian, Sumin Hou, Huafang Zhang, Jiazhen Yang, Gencai Pan, Huiping Gao, Wenwu You, Zhenlong Zhang, Baohua Zhu, Yanli Mao
Summary: High quality and less defective BA(2)FAPb(2)I(7) perovskite films were obtained by a simple one-step spin coating method with rare earth doping assisted crystal growth. The photoconductor photodetectors (PDs) fabricated using these films exhibited remarkable balance detect properties with low dark current, high on/off ratio, high responsivity, outstanding detectivity, and fast response speed. This work not only provides an indubitably feasible way for fabricating quasi-2D perovskite PDs, but also offers a clear direction for enhancing the performance of other perovskite optoelectronics.
APPLIED PHYSICS LETTERS
(2023)
Proceedings Paper
Optics
Baohua Zhu, Fangfang Wang, Yaolu Li, Yuzong Gu
ELEVENTH INTERNATIONAL CONFERENCE ON INFORMATION OPTICS AND PHOTONICS (CIOP 2019)
(2019)
Proceedings Paper
Nanoscience & Nanotechnology
Baohua Zhu, Fangfang Wang, Yuzong Gu
NANOPHOTONICS AND MICRO/NANO OPTICS IV
(2018)
Article
Chemistry, Physical
Baohua Zhu, Fangfang Wang, Peng Li, Chong Wang, Yuzong Gu
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2018)
Article
Optics
Chong Wang, Fangfang Wang, Baohua Zhu, Shuxi Dai, Yuzong Gu, Jiayu Zhang
APPLIED PHYSICS B-LASERS AND OPTICS
(2017)
