Article
Chemistry, Multidisciplinary
Shaojie Liu, Yufei Shu, Meiyi Zhu, Haiyan Qin, Xiaogang Peng
Summary: Most bulk semiconductors show an increase in band-gap energy with decreasing temperature. However, semiconductor quantum dots (QDs) exhibit non-monotonic temperature dependence of the emission energy at low temperatures. This study uses stable and efficient CdSe/CdS/ZnS QDs as a model system to quantitatively explain the origins of the anomalous emission red-shift at temperatures below 40 K. The red-shift is attributed to the temperature-dependent population of band-edge exciton fine levels, enhanced electron-optical phonon coupling due to increasing population of dark excitons, and temperature-dependent electron-acoustic phonon coupling.
Article
Nanoscience & Nanotechnology
Giacomo Biagiotti, Andrea Angeli, Arianna Giacomini, Gianluca Toniolo, Luca Landini, Gianluca Salerno, Lorenzo Di Cesare Mannelli, Carla Ghelardini, Tommaso Mello, Silvia Mussi, Cosetta Ravelli, Marcello Marelli, Stefano Cicchi, Enzo Menna, Roberto Ronca, Claudiu T. Supuran, Barbara Richichi
Summary: A quantum dot-based fluorescent glyconanoprobe with a specific ligand coating was designed and synthesized in this study, targeting membrane-anchored overexpressed hCA IX on bladder cancer cells, with monosaccharide residues ensuring dispersibility in the biological medium and quantum dots imparting optical/fluorescence properties.
ACS APPLIED NANO MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Xiaoqi Hou, Haiyan Qin, Xiaogang Peng
Summary: Auger recombination is effectively reduced in high-quality quantum dots by enhancing dielectric screening of band-edge carriers with additional ZnS shells. The volume scaling of negative-trion Auger lifetime is achieved with ZnS shells, which can be less than half the volume of QDs without these shells, while also enhancing the biexciton emission quantum yield. The engineering of Auger effects through dielectric screening presents new opportunities for improving emission properties in multicarrier states of quantum dots.
Article
Chemistry, Physical
Yuzhe Wang, Yueqi Zhong, Jiangzhi Zi, Zichao Lian
Summary: In this study, CdSe@CdS@ZnS heterojunction nanocrystal hybrids were designed to improve the photoluminescence performance of conventional single-component quantum dots. The results demonstrate that the energy band structure is transformed and the photoluminescence lifetime and quantum efficiency are increased after the growth of ZnS.
Article
Chemistry, Multidisciplinary
Hyo-Geun Kwon, Taesoo Lee, Kihyo Kim, Do-Hyun Kim, Haewoon Seo, O-Pil Kwon, Jeonghun Kwak, Sang-Wook Kim
Summary: This article introduces an approach for synthesizing AgInZnS/CdS/ZnS core-shell-shell quantum dots (QDs) that show exceptional stability and electroluminescence (EL) performance. By incorporating a cadmium sulfide (CdS) interlayer between an AgInZnS (AIZS) core and a zinc sulfide (ZnS) shell, the diffusion of Zn ions into the AIZS core and the cation exchange at the core-shell interface are prevented. This leads to the formation of a uniform and thick ZnS shell (2.9 nm), significantly enhancing the stability and increasing the photoluminescence quantum yield (87.5%) of the QDs. The potential of AIZS/CdS/ZnS QDs in electroluminescent devices is evaluated, achieving an external quantum efficiency of 9.6% at 645 nm. These findings highlight the importance of uniform and thick ZnS shells in improving the stability and EL performance of QDs.
Article
Chemistry, Physical
A. D. Kurilov, D. N. Chausov, V. V. Osipova, R. N. Kucherov, V. V. Belyaev, Y. G. Galyametdinov
Summary: This work focuses on synthesizing highly luminescent hybrid CdSe/CdS core/shell quantum dots and doping them into a nematic liquid crystal to obtain new composites. The sizes of the quantum dot cores and additional ZnS shells are correlated with the luminescence and dielectric characteristics of the composites.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Analytical
Luping Tang, Yangyang Zhang, Chen Liao, Yingqing Guo, Yingtao Lu, Yixuan Xia, Yiwei Liu
Summary: In this study, the temperature-dependent photoluminescence (PL) properties of CdS/ZnS core/shell quantum dots (QDs) were investigated. The results showed that the band-edge emission (BEE) intensity decreased with increasing temperature, while the surface-state emission (SSE) intensity first increased and then decreased. The PL spectra exhibited a redshift in peak energies and an increase in full width at half-maximum (FWHM) as the temperature increased. Furthermore, the CIE chromaticity coordinates showed a dramatic change with temperature. These findings suggest that CdS/ZnS core/shell QDs have potential applications as temperature sensors.
Article
Materials Science, Multidisciplinary
Aneeqa Sabah, Imrana Shafaqat, Amin Naifar, Hind Albalawi, Mohammed S. Alqahtani, M. G. B. Ashiq, Syeda Ammara Shabbir
Summary: Highly emissive core-multi-shell (CdSe/CdS/ZnS) quantum dots (QDs) with sizes ranging from 2 nm to 5 nm were synthesized using the hot injection method. Polymer capping agents were employed to enhance the QDs' lifetime without the need for a protective atmosphere. The absorption spectra of CdSe/CdS and CdSe/CdS/ZnS displayed a red shift compared to CdSe core, with peaks at 362 nm, 365 nm, 558 nm, and 556 nm. The band gaps measured by voltammetry (Eg 2.09 eV) were in good agreement with the UV-visible spectroscopic data (Eg 2.65 eV). XRD spectra confirmed the quantum confinement effect, showing distinct peaks corresponding to the (111), (220), and (311) planes of cubic structures for CdSe, CdSe/CdS, and CdSe/CdS/ZnS, respectively. The effective mass model was used to calculate the linear and nonlinear optical susceptibilities and absorption coefficients.
Article
Nanoscience & Nanotechnology
Xinyuan Sun, Mengyao Shi, Chun Zhang, Jinting Yuan, Min Yin, Shichao Du, Shuai Yu, Bowei Ouyang, Fumin Xue, Sheng-Tao Yang
Summary: In this study, fluorescent Ag-In-S/ZnS quantum dots (AIS/ZnS QDs) with red emission were developed for fast tumor drainage lymph node imaging in vivo. The AIS/ZnS QDs were shown to migrate efficiently to sentinel lymph nodes, enabling effective imaging within 10 minutes upon intratumoral injection. Overall, AIS/ZnS QDs demonstrated high performance as an imaging reagent for tumor drainage lymph nodes.
ACS APPLIED NANO MATERIALS
(2021)
Article
Chemistry, Analytical
Satyanarayana Swamy Vyshnava, Gayathri Pandluru, Kanderi Dileep Kumar, Shiva Prasad Panjala, Kameshpandian Paramasivam, Swathi Banapuram, Roja Rani Anupalli, Muralidhara Rao Dowlatabad
Summary: Quantum dots with chemical composition QDCdSe/ZnS_Ni650 were successfully synthesized and characterized using X-ray diffraction (XRD). The ferromagnetic data revealed the magnetic behavior of the QDCdSe/ZnS_Ni650. The optical absorption measurements showed a redshift in band gap compared to bulk CdSe. Additionally, the QDCdSe/ZnS_Ni650 were effectively taken up by cell lines for bioimaging and sorting applications.
Article
Chemistry, Physical
Jiao Zhang, Xiaofeng Sun, Jinyuan Ma, Zao Yi, Tao Xian, Shifa Wang, Guorong Liu, Xiangxian Wang, Hua Yang
Summary: Rational design of heterostructures is an effective strategy for enhancing the photocatalytic activity of semiconductors. In this study, a dual Z-scheme CdS/ZWO/ZnS heterojunction photocatalyst was synthesized by assembling zero-dimensional CdS and ZnS quantum dots onto one-dimensional ZnWO4 nanorods. The photocatalytic experiments demonstrated that the dual Z-scheme heterojunction photocatalyst exhibited significantly higher photodegradation activity compared to individual CdS, ZnS, and binary CdS/ZWO and ZnS/ZWO heterojunctions. The characteristics and photocatalytic mechanism of the CdS/ZWO/ZnS photocatalysts were investigated using various measurement techniques and computational calculations.
APPLIED SURFACE SCIENCE
(2023)
Article
Optics
Vuyelwa Ncapayi, Neethu Ninan, Thabang C. Lebepe, Sundararajan Parani, Aswathy Ravindran Girija, Richard Bright, Rodney Maluleke, Olanrewaju A. Aladesuyi, Tetsuya Kodama, Krasimir Vasilev, Oluwatobi S. Oluwafemi
Summary: In this study, NIR emitting colloidal Mn-doped CuInSe/ZnS QDs were synthesized via the hydrothermal method and showed good photostability. The QDs exhibited selective imaging of Gram-positive bacteria and prostate cancer cells, making them potential candidates for cancer-bacteria dual-imaging in biomedicine.
JOURNAL OF LUMINESCENCE
(2023)
Article
Chemistry, Multidisciplinary
Kai-Ping Chang, Yu-Cheng Yeh, Chung-Jui Wu, Chao-Chun Yen, Dong-Sing Wuu
Summary: CdSe/CdS core/shell quantum dots with different oleylamine (OLA) concentrations were synthesized using a one-pot method. The presence of ZnS diffraction peaks indicated the formation of a ZnS shell on the CdSe/CdS core. Interestingly, QDs with higher OLA concentration exhibited diffraction peaks of ZnS/ZnO, showing better thermal stability and slower decay in photoluminescence intensity. These QDs with tunable emission wavelength are suitable for micro-LED display applications.
Article
Chemistry, Applied
Mei Hu, Xiaofei Hu, Guoqiang Wang, Yongxia Cheng, Xiaoling Yu, Xianqing Huang, Yu Li
Summary: A portable fluorescence immunosensor based on CdSe/CdS/ZnS quantum dots (QDs) was developed for the precise quantification of olaquindox (OLA). The QDs labeled anti-OLA antibody served as a bioprobe and greatly enhanced the sensitivity of the lateral flow test strip. The method achieved quantitative results within 8 minutes using a fluorescent strip scan reader, with a detection limit of 0.12 μg/kg, 2.7 times more sensitive than the conventional colloidal gold-based strips. Acceptable recovery rates of 85.0%-95.5% were obtained for spiked samples. This QDs-based strip immunoassay method is suitable for on-site detection and rapid initial screening of OLA in swine feedstuff, and has the potential for detecting other veterinary drugs to ensure food safety.
Article
Chemistry, Physical
Cong Li, Huan Li, Zhinan Zhu, Tong Yin, Zhenni Wang, Peipei Li, Chengxin Zeng, Fu Yang, Peng Zhong, Nuanyang Cui, Chunhui Shou
Summary: CdS/ZnS quantum dots can achieve the dual effects of waterproofing hydrophobic and defect passivation of perovskite films, improving the efficiency and stability of the device.
JOURNAL OF POWER SOURCES
(2022)
