Article
Materials Science, Multidisciplinary
Saranya Reddy Shriram, Debiprasad Panda, Ravindra Kumar, Jhuma Saha, Binita Tongbram, Manas Ranjan Mantri, Sanowar Alam Gazi, Arjun Mandal, Subhananda Chakrabarti
Summary: This study achieved a uniform size distribution of multistack InAs/InGaAs sub-monolayer quantum dots by capping with varying thickness of InxGa1-xAs layer. The use of an optimal capping layer thickness alleviated dot segregation and surface diffusion effects, leading to the growth of nearly defect-free quantum dot heterostructure. Experimental calculations and analysis were performed on photoluminescence and PL excitation spectroscopy to understand the effects of capping layers on quantum dot properties. High-resolution X-ray diffraction and Raman measurements were used to inspect the interfacial structural quality and strain relaxation in quantum dots. The sample with a 2 ML capping layer thickness showed superior results in terms of photoluminescence emission and strain, which is beneficial for photodetector applications in the short-wave infrared regime.
Article
Physics, Multidisciplinary
Guangze Lu, Zunren Lv, Zhongkai Zhang, Xiaoguang Yang, Tao Yang
Summary: The effects of Sb component in cap layers on the band alignment of InAs/GaAsSb quantum dots were studied to achieve quantum dots with a long carrier lifetime. Results showed that with increasing Sb composition, the quantum dots exhibited a red-shift and broadening photoluminescence. Additionally, quantum dots with a high Sb component showed longer carrier lifetimes compared to those with a low Sb component. These findings are significant for the development of high conversion efficiency intermediate-band quantum dot solar cells and other opto-electronic devices.
Article
Nanoscience & Nanotechnology
H. Mohammadi, R. C. Roca, I Kamiya
Summary: Strain control and photoluminescence enhancement of InAs surface quantum dots have been achieved by introducing buried quantum dots. The study shows that strain and related effects dominate the electronic properties of the quantum dots, and buried quantum dots act as effective carrier reservoirs.
Article
Physics, Applied
Motoyuki Tanaka, Keichiro Banba, Tomah Sogabe, Koichi Yamaguchi
Summary: InAs in-plane ultrahigh-density quantum dots (IP-UHD QDs) were grown on GaAsSb/GaAs(001) by molecular beam epitaxy and successfully introduced into the active layer of a ridge-waveguide AlGaAs/GaAs laser, achieving stable laser operation up to 80 degrees Celsius. The IP-UHD QD lasers have the same low internal loss as conventional QD lasers. Improved uniformity in IP-UHD QDs holds the promise of achieving ultralow threshold current.
APPLIED PHYSICS EXPRESS
(2021)
Article
Chemistry, Physical
Biswajit Bhattacharyya, Arpita Mukherjee, Rekha Mahadevu, Anshu Pandey
Summary: The research focuses on the electronic structure and manipulation of spontaneous emission lifetimes of copper-doped CdZnSe quantum dots. By varying the density of electronic states involved in the emission process, the spontaneous emission lifetimes can be continuously tuned from nanoseconds to microseconds, representing a significant advancement in luminescent materials.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Z. H. Yao, X. Wang, H. M. Chen, T. Wang, L. Qin, J. Liu, Z. Y. Zhang
Summary: The modulation p-doping technique improves the carrier dynamics process of quantum dot structures, increasing the relaxation rate and ground state saturation gain. By using a designed facet coating, the lasers can achieve ground state lasing at short cavity lengths.
Article
Chemistry, Multidisciplinary
Dongxu Zhu, Fulvio Bellato, Houman Bahmani Jalali, Francesco Di Stasio, Mirko Prato, Yurii P. Ivanov, Giorgio Divitini, Ivan Infante, Luca De Trizio, Liberato Manna
Summary: This study investigates the role of ZnCl2 as an additive in the synthesis of InAs nanocrystals (NCs) using tris(dimethylamino)arsine. It is found that ZnCl2 not only improves the size distribution of InAs NCs, but also acts as a ligand to passivate their surface. The addition of a Zn precursor enables the subsequent growth of a ZnSe shell, resulting in InAs@ZnSe core@shell NCs with high quantum yield.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Artur Tuktamyshev, Stefano Vichi, Federico Guido Cesura, Alexey Fedorov, Giuseppe Carminati, Davide Lambardi, Jacopo Pedrini, Elisa Vitiello, Fabio Pezzoli, Sergio Bietti, Stefano Sanguinetti
Summary: The role of strain relaxation and capping overgrowth in the self-assembly of InAs quantum dots by droplet epitaxy is investigated in detail. Comparisons between quantum electronic calculations and emission properties of the quantum dots reveal a strong quenching effect on the emission from larger quantum dots. Detailed analysis of the surface morphology during the capping procedure shows plastic relaxation of the quantum dots above a critical size.
Article
Chemistry, Multidisciplinary
Lior Asor, Jing Liu, Yonatan Ossia, Durgesh C. Tripathi, Nir Tessler, Anatoly Frenkel, Uri Banin
Summary: This study demonstrates the successful p-type doping of originally n-type InAs nanocrystals by post-synthetically doping with Cd, showing remarkable stability of hole conduction, mobility, and hysteretic behavior in Cd-doped InAs FETs compared to intrinsic InAs NCs FETs when exposed to air. Cd acts as a p-type dopant and also protects the nanocrystals from oxidation, setting the stage for implementing doped nanocrystal systems in printed electronic devices.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Naoto Kumagai, Xiangmeng Lu, Yasuo Minami, Takahiro Kitada, Toshiro Isu
Summary: The study focused on determining the lateral mobility of photocarriers and activation energy of the photocurrent in stacked InAs quantum dot layers, which are crucial for photoconductive antennas operating for THz wave detection.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2021)
Article
Materials Science, Multidisciplinary
Pei-Lun Hsieh, Gautam Kumar, Yen-Yu Wang, Yu-Jung Lu, Lih-Juann Chen, Michael H. Huang
Summary: By cutting an intrinsic {0001} GaN wafer to expose the {1010}/{1100} side faces, the conductivity properties with respect to crystal faces can be examined. The {1010} face shows a 10-fold higher photoluminescence peak intensity than the {0001} face, while the {0001} face is 60-fold more conductive at 6V than the {1010} face, indicating the presence of an electrical facet effect. The asymmetric I-V curves obtained by connecting to both faces simultaneously demonstrate the potential for fabricating transistors using this behaviour.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Omer Arif, Valentina Zannier, Francesca Rossi, Daniele Ercolani, Fabio Beltram, Lucia Sorba
Summary: The study presents the self-catalyzed growth of InAs/InSb/InAs axial heterostructured nanowires with a single defect-free InSb quantum dot on Si substrates using chemical beam epitaxy. By systematically varying the growth parameters, the researchers found that the growth temperature strongly influences the axial and radial growth rates of the top InAs segment, allowing for control over the thickness of the InAs shell around the InSb quantum dot. Additionally, the study highlights the importance of In diffusion paths and the interplay of growth mechanisms in determining the final shape of the nanowires.
Article
Chemistry, Multidisciplinary
Zheming Liu, Roberta Pascazio, Luca Goldoni, Daniela Maggioni, Dongxu Zhu, Yurii P. P. Ivanov, Giorgio Divitini, Jordi Llusar Camarelles, Houman Bahmani Jalali, Ivan Infante, Luca De Trizio, Liberato Manna
Summary: We successfully synthesized colloidal InAs nanocrystals (NCs) using amino-As and ligands different from the commonly employed oleylamine (OA). The combination of TOA and OA allowed for good control over the size distribution of the InAs NCs, with a volume ratio of 4:1 generating InAs tetrapods with arm lengths of 5-6 nm. These NCs are entirely zinc-blende and have a narrow excitonic peak at 950 nm in absorption. The use of mixtures of ligands improves control over the size and size distribution of InAs NCs.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Marwa Ahmed El-Naka, A. El-Dissouky, G. Y. Ali, Shaker Ebrahim, Azza Shokry
Summary: Dual functional garlic-capped silver nanoparticles were used as fluorescent sensors for detecting acrylamide and acetone, showing high selectivity and sensitivity. The technique had wide linear responses and low detection limits, with good repeatability and reproducibility.
Article
Optics
Rayhani Jawher, Mehrez Oueslati, Vincent Sallet, Jean-Christophe Harmand, Radhwen Chtourou
Summary: Temperature-dependent photoluminescence measurements were performed on self-assembled InAs quantum dots grown by molecular beam epitaxy. Non-monotonic evolutions of the PL spectral parameters as a function of temperature were observed in the low-temperature regime. The anomalous increase in the integrated intensity and sigmoidal variation of the PL peak energy with increasing temperature were attributed to the optical emission from deep states in the quantum dots. A rate equation model successfully described the evolution of the integrated PL intensity with temperature, providing insight into the thermally activated intra-dot redistribution of carriers.
JOURNAL OF LUMINESCENCE
(2023)
Article
Nanoscience & Nanotechnology
Xin Zhang, Hui Yang, Yunyan Zhang, Huiyun Liu
Summary: This study systematically analyzes the challenges in achieving vertically-standing nanowire lasers and proposes a nanowire superlattice distributed Bragg reflector to greatly enhance the performance of the lasers.
Article
Engineering, Electrical & Electronic
Charlotte Ovenden, Ian Farrer, Maurice S. Skolnick, Jon Heffernan
Summary: Atomic force microscopy (AFM) assisted local anodic oxidation (LAO) is a low contamination method for semiconductor fabrication. In this study, we demonstrate the fabrication of deep and highly reproducible nanohole arrays on InP using LAO. The size and depth of the nanoholes and nano-oxide mounds can be controlled independently by altering AFM tip bias and humidity. The oxidation mechanism of semi-insulating InP during LAO is found to be similar to that of plasma oxidation.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
Dominic Hallett, Andrew P. Foster, David Whittaker, Maurice S. Skolnick, Luke R. Wilson
Summary: This study demonstrates numerically that spin-dependent chiral coupling can be achieved by embedding a quantum emitter with circularly polarized optical transitions in a waveguide-coupled nanocavity. The experimentally feasible cavity design supports high chiral contrast, efficient cavity-waveguide coupling, and enhanced light-matter interaction strength.
Article
Physics, Applied
Feng Li, Yiming Li, L. Giriunas, M. Sich, D. D. Solnyshkov, G. Malpuech, A. A. P. Trichet, J. M. Smith, E. Clarke, M. S. Skolnick, D. N. Krizhanovskii
Summary: In this study, a tunable open-access microcavity was established to achieve polariton condensation by controlling the light-matter coupling strength through nanopositioners. The experimental results showed that the lowest condensation threshold always occurred at a fixed energy trap depth for different coupling strengths.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Applied
Hyun-Ju Ahn, Yudong Jang, Donghan Lee
Summary: In this study, a new method for generating linearly polarized single photons using an elliptic mesa is proposed and verified by finite-difference time-domain simulations. It is found that single photons emitted from the center of a 300 nm mesa exhibit high linear polarization.
APPLIED SCIENCE AND CONVERGENCE TECHNOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Dean A. Houston, Louise A. Stephen, Soher N. Jayash, Katherine Myers, Kirsty Little, Mark Hopkinson, Andrew A. Pitsillides, Vicky E. MacRae, Jose Luis Millan, Katherine A. Staines, Colin Farquharson
Summary: The administration of intermittent parathyroid hormone (iPTH) can enhance bone mineralization and osteogenesis by regulating the expression of key enzymes such as PHOSPHO1.
CELL BIOCHEMISTRY AND FUNCTION
(2023)
Article
Orthopedics
Mark Hopkinson, Gareth Jones, Lucinda Evans, Stephanie Gohin, Ran Magnusdottir, Phil Salmon, Chantal Chenu, Richard Meeson, Behzad Javaheri, Andrew A. Pitsillides
Summary: The need to better understand bone repair processes under different pathophysiological states due to fracture burden highlights the importance of evaluating the structural and material properties of mineralized callus for restoring biomechanical stability. This study shares a new automatic method for segmenting callus in micro-CT tomograms, allowing for objective and quantitative analysis of bone fracture microarchitecture. The results demonstrate that the automatic segmentation reliably and consistently segments callus from cortical bone, providing a faster and less user-dependent tool for studying bone callus in fractures and potentially other applications.
JOURNAL OF ORTHOPAEDIC RESEARCH
(2023)
Editorial Material
Optics
Junjie Yang, Mingchu Tang, Siming Chen, Huiyun Liu
Summary: The realization of on-chip light sources enables the complete integration of Si-based photonic integrated circuits (PICs).
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Yun-Ran Wang, Im Sik Han, Mark Hopkinson
Summary: Regular arrays of single III-V quantum dots and quantum rings with high uniformity and good optical quality have been fabricated using molecular beam epitaxy assisted by in situ direct laser interference patterning. These structures serve as a next-generation platform for functional nanophotonic devices and contribute to the future quantum revolution.
Article
Optics
Anthonin Delphan, Maxim N. Makhonin, Tommi Isoniemi, Paul M. Walker, Maurice S. Skolnick, Dmitry N. Krizhanovskii, Dmitry V. Skryabin, Jean-Francois Carlin, Nicolas Grandjean, Raphael Butte
Summary: We observed polariton lasing in micro-ring resonators based on GaN/AlGaN slab waveguides in the UV spectral range, with stimulated polariton relaxation into multiple ring resonator modes. The strong exciton-photon coupling regime was confirmed by the reduction of the free spectral range and the blueshift of the exciton-like modes with increasing pulse energy. The absence of broadening in the exciton emission further confirmed lasing at low electron-hole densities. Overall, our work paves the way for the development of novel UV devices based on high-speed slab waveguide polariton geometry operating up to room temperature and integrated into complex photonic circuits.
Article
Engineering, Electrical & Electronic
Daqian Guo, Jian Huang, Mourad Benamara, Yuriy I. Mazur, Zhuo Deng, Gregory J. Salamo, Huiyun Liu, Baile Chen, Jiang Wu
Summary: We successfully integrated submonolayer quantum dot quantum cascade detectors (SML QD QCDs) on Si substrates via direct growth, reducing the threading dislocation density to a record level. High-quality InGaAs/GaAs SML QDs were observed on silicon for the first time. The as-grown SML QD QCDs on Si exhibited a normal incident photoresponse temperature up to 160 K, indicating their potential for scalable and affordable photodetectors and infrared focal plane arrays.
IEEE JOURNAL OF QUANTUM ELECTRONICS
(2023)
Article
Physics, Applied
F. T. Albeladi, S. Gillgrass, J. Nabialek, P. Mishra, R. Forrest, T. R. Albiladi, C. P. Allford, H. Deng, M. Tang, H-y Liu, S. Shutts, P. M. Smowton
Summary: InAs quantum dot ridge waveguide lasers with single-port multi-mode-interference-reflectors (MMIR) and single-cleaved reflectors were designed, fabricated, and characterized for optoelectronic-integrated-circuits. Simulations showed high fundamental mode reflectivity (> 80%) and good selectivity against higher order modes. The deep-etched MMIR lasers with 0.5 mm long cavities had a lower threshold current of 24 mA compared to standard Fabry-Perot cleaved-cleaved FP-RWG lasers of the same length at 25 degrees C, and 56 mA compared to 102 mA at 55 degrees C. The MMIR lasers exhibited stable ground state operation up to 50 degrees C and showed potential as small footprint sources for integrated photonics.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Quantum Science & Technology
Hamidreza Siampour, Christopher O'Rourke, Alistair J. Brash, Maxim N. Makhonin, Rene Dost, Dominic J. Hallett, Edmund Clarke, Pallavi K. Patil, Maurice S. Skolnick, A. Mark Fox
Summary: Quantum states of light and matter can be manipulated on the nanoscale to aid the implementation of scalable photonic quantum technologies. A nanophotonic waveguide platform with embedded quantum dots (QDs) was demonstrated, allowing for Purcell-enhanced emission and strong chiral coupling. Record-large radiative decay rate and Purcell enhancement were achieved through electric-field tuning and quasi-resonant excitation. The results show promising prospects for using QDs in scalable implementations of on-chip spin-photonics relying on chiral quantum optics.
NPJ QUANTUM INFORMATION
(2023)
Article
Optics
D. H. Ahn, Y. D. Jang, J. S. Baek, S. I. Park, J. D. Song, D. Lee
Summary: High-brightness single photon sources (SPSs) are crucial for quantum information processing. Challenges remain in matching the emission wavelength of a quantum dot to the narrow spectral bandwidth of high-Q cavity structures. A highly bright and broadband QD SPS is proposed, which can be deterministically fabricated using a simple method. Experimental results show a brightness of 51.6% +/- 2% and pure single photon emission, indicating the potential of this approach for practical high-brightness QD SPS without expensive lithography and etching processes.
Article
Optics
Jingwen Ma, Taojie Zhou, Mingchu Tang, Haochuan Li, Zhan Zhang, Xiang Xi, Mickael Martin, Thierry Baron, Huiyun Liu, Zhaoyu Zhang, Siming Chen, Xiankai Sun
Summary: This study successfully realizes topological Dirac-vortex microcavity lasers on a silicon substrate and observes room-temperature continuous-wave linearly polarized vertical laser emission. These lasers exhibit topological robustness, maintaining a stable wavelength despite variations in the cavity size, and their free spectral range does not follow the universal inverse scaling law with the cavity size.
LIGHT-SCIENCE & APPLICATIONS
(2023)
