Article
Materials Science, Multidisciplinary
Philipp Storm, Susanne Selle, Holger von Wenckstern, Marius Grundmann, Michael Lorenz
Summary: Transparent, p-type semiconductor copper iodide (CuI) thin films were grown via pulsed laser deposition on SrF2(111) using water soluble sacrificial layers of sodium bromide (NaBr). The resulting CuI thin films are single crystalline with reduced surface roughness compared to epitaxial CuI grown with rotational domains on other templates. The CuI thin films were subsequently transferred onto glass using epoxy/glue and dissolution of NaBr in a water-vapor atmosphere.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Physics, Multidisciplinary
N. Carlon Zambon, Z. Denis, R. De Oliveira, S. Ravets, C. Ciuti, I. Favero, J. Bloch
Summary: By embedding quantum wells into semiconductor microresonators, tightly confined and mutually interacting excitonic, optical, and mechanical modes can coexist. In this study, we investigate the parametric modulation of optical and excitonic resonances by the interaction with a mechanical mode in the strong exciton-photon coupling regime. We find that the exciton-phonon coupling in semiconductors leads to a significant enhancement of polariton-phonon interactions, making it possible to achieve near-unity single-polariton quantum cooperativity on current semiconductor resonator platforms. We also analyze how polariton nonlinearities affect dynamical backaction, altering the ability to cool or amplify the mechanical motion.
PHYSICAL REVIEW LETTERS
(2022)
Correction
Engineering, Electrical & Electronic
J. F. Cheng, X. Li, X. M. Shao, T. Li, Y. J. Ma, Y. Gu, S. Y. Deng, Y. G. Zhang, H. M. Gong
Summary: The above article discusses the affiliations of the authors.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2022)
Article
Computer Science, Information Systems
Ahid S. Hajo, Sascha Preu, Leonid Kochkurov, Thomas Kusserow, Oktay Yilmazoglu
Summary: This study investigates fully integrated THz detectors using silver NWs as bridge contacts on highly doped GaAs and InGaAs layers, achieving improved performance at zero bias with a maximum cut-off frequency of 2.6 THz. Initial THz measurements suggest a responsivity of 0.81 A/W and low NEP value of 7 pW/root Hz at 1 THz.
Article
Chemistry, Multidisciplinary
Sergey V. Balakirev, Natalia E. Chernenko, Mikhail M. Eremenko, Oleg A. Ageev, Maxim S. Solodovnik
Summary: This study proposes a new approach to control the size of nanostructures formed by droplet epitaxy using ultra-low group-V flux. It demonstrates that larger droplets can be reduced to stable, small-sized nanostructures suitable for quantum dot applications, while smaller droplets are unstable and difficult to control. The research expands the capabilities of droplet epitaxy by observing phenomena related to the transformation of droplets into dots, rings, and holes under specific growth conditions.
Article
Engineering, Electrical & Electronic
Ioannis E. Fragkos, Wei Sun, Damir Borovac, Renbo Song, Jonathan J. Wierer, Nelson Tansu
Summary: This study investigates an active region design based on InGaN / delta-InN quantum well (QW) for potential high-efficiency visible light emitters. The results demonstrate a large wavelength redshift and an increase in the electron-hole wavefunction overlap for the delta-structure compared to the conventional InGaN QW.
IEEE JOURNAL OF QUANTUM ELECTRONICS
(2022)
Article
Chemistry, Multidisciplinary
Pan Xia, Bin Sun, Margherita Biondi, Jian Xu, Ozan Atan, Muhammad Imran, Yasser Hassan, Yanjiang Liu, Joao M. Pina, Amin Morteza Najarian, Luke Grater, Koen Bertens, Laxmi Kishore Sagar, Husna Anwar, Min-Jae Choi, Yangning Zhang, Minhal Hasham, F. Pelayo Garcia de Arquer, Sjoerd Hoogland, Mark W. B. Wilson, Edward H. Sargent
Summary: This research reports a novel co-passivation strategy for fabricating indium arsenide CQD photodetectors, which maintains charge carrier mobility and improves passivation by using methyl ammonium acetate and indium chloride as ligands, resulting in a doubling of the photoluminescence lifetime. The resulting devices achieved a 37% external quantum efficiency (EQE) at 950 nm, the highest reported value for InAs CQD photodetectors.
ADVANCED MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
M. N. Bataev, M. A. Chukeev, M. M. Sharipova, P. A. Belov, P. S. Grigoryev, E. S. Khramtsov, I. Ignatiev, S. A. Eliseev, V. A. Lovtcius, Yu. P. Efimov
Summary: This paper presents a comprehensive study of both light-hole and heavy-hole excitons in quantum wells, focusing on their energy positions and interactions with light. The findings show that the corrections to the exciton energy due to mixing are small, and the oscillator strength of light-hole excitons is significantly lower than that of heavy-hole excitons. This research is important for understanding the characteristics of excitons in semiconductor materials.
Article
Physics, Applied
Yi Zhang, Xuguang Jia, Shuang Liu, Kefan Wu, Jiayu Zhang, Gavin Conibeer
Summary: Studies show that slowing down carrier intervalley scattering can extend the carrier lifetime, while slowing down the thermalization rate within the gamma valley is mainly influenced by the phonon bottleneck effect. However, the correlation between slowing down carrier relaxation rate through IVS and PBE remains unclear.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Jong Yul Park, Byoung-Gue Min, Jong-Min Lee, Woojin Chang, Dong Min Kang, E-San Jang, Junhyung Kim, Jeong-Gil Kim
Summary: The authors propose criteria for recess etching in order to fabricate T-gates for InGaAs high electron mobility transistors (HEMTs). By patterning additional rectangular pads on the source and drain metals during e-beam lithography, they are able to measure the drain-to-source resistance (R-ds) and current (I-ds). The ratio (& UGamma;) of R-ds and I-ds before and after etching can be used as a criterion to determine the optimal time to stop the etching process. By applying the proposed criteria, the authors have successfully fabricated InGaAs metamorphic HEMTs with excellent performance.
ELECTRONICS LETTERS
(2023)
Article
Chemistry, Physical
Chaojie Li, Jiyou Zhong
Summary: A novel Cr3+-doped garnet phosphor Y3In2Ga3O12:Cr3+ is discovered, which can emit broadband NIR light upon 450 nm excitation. This material exhibits high efficiency and thermal stability, and the NIR pc-LED device fabricated using it shows better performance than devices made from other reported NIR materials.
CHEMISTRY OF MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Yanting Kong, Rong Ma, Bin Shen, Qingnan Yu
Summary: In this paper, a simple and effective detection method for the thickness fluctuation of InGaAs layers in InxGa1-xAs-based IRC structure is proposed through point-to-point acquisition. The relationship between InxGa1-xAs thickness and spectral intensity is established, and the thickness fluctuation of normal and indium-deficient InGaAs layers is determined by comparing the intensity of dual peaks, which are caused by indium atom migration.
IEEE PHOTONICS JOURNAL
(2022)
Article
Materials Science, Multidisciplinary
Asta Griguceviciene, Putinas Kalinauskas, Laurynas Staisiunas, Konstantinas Leinartas, Algirdas Selskis, Eimutis Juzeliunas
Summary: This study presents a photoelectrochemical (PEC) method for depositing silicon and silicon-carbon layers at 40°C using silicon tetrachloride as a precursor. The semiconductor substrates are activated by white LED illumination to make them conductive, allowing for the deposition of amorphous layers. The proposed method has potential applications in batteries, anti-corrosion coatings, photovoltaics, and PEC electrodes for hydrogen production.
Article
Nanoscience & Nanotechnology
Thomasina Zaengle, Ursula J. Gibson, Thomas W. Hawkins, Colin McMillen, Basanta Ghimire, Apparao M. Rao, John Ballato
Summary: A novel extension to the molten core method was employed to fabricate a glass-clad, crystalline gallium arsenide (GaAs) core fiber for the first time. By using tin as a flux, long lengths of glass-clad, crystalline GaAs-containing fibers were successfully drawn at a temperature where volatility is negligible. Laser annealing was utilized to differentiate the Sn and GaAs phases along the fiber. This work presents a new tool for scalable fabrication of glass-clad crystalline core materials and enables the development of novel and useful optoelectronic devices within the fiber.
Article
Materials Science, Multidisciplinary
B. O. Alaydin, D. Altun, E. Ozturk
Summary: This paper studies the optical properties of semi-elliptical InAs quantum dots embedded in GaAs. It shows that the wetting layer thickness has a small effect on the transition between energy levels 1 and 2, but has a significant impact on the dipole moment matrix element (DMME) of the transitions between energy levels 2 and 3, and 1 and 3. The linear absorption coefficients reach their maximum values at a wetting layer thickness of 4 A. Additionally, applying an electric field in the axial direction enhances the DMME of the transitions between energy levels 2 and 3, and 1 and 3, resulting in very high linear absorption coefficients.
Article
Materials Science, Ceramics
F. H. Bhat, G. Anjum, Ravi Kumar, Manzoor A. Malik, R. J. Choudhary, D. K. Shukla
Summary: Polycrystalline LaMn1-xCoxO3 (0.1 <= x <= 0.5) samples synthesized using conventional ceramic method exhibit strong magnetic properties with double transition and spin glass state. These characteristics are mainly influenced by the interactions between Co and Mn ions, showing significant magnetoresistance effects.
CERAMICS INTERNATIONAL
(2021)
Article
Physics, Condensed Matter
Sumit Bhardwaj, J. D. Sharma, Subhash Chand, K. K. Raina, Ravi Kumar
Summary: Lead-free ceramic-polymer nanocomposites were synthesized using the solution casting method, with homogeneously dispersed BLT ceramic particles enhancing the electroactive phases of PVDF. The nanocomposites exhibited superior dielectric and ferroelectric properties, showing potential in flexible sensors, data storage, and energy harvesting applications.
SOLID STATE COMMUNICATIONS
(2021)
Article
Chemistry, Inorganic & Nuclear
Pankaj Bhardwaj, Jarnail Singh, Rajesh Kumar, Ravi Kumar, Vikram Verma
Summary: In this study, the suitability of chromium oxide as diluted magnetic oxide was systematically investigated, with nanoparticles doped with Ni2+ ions successfully synthesized. Various analyses confirmed the structural characteristics of the nanoparticles and revealed the presence of oxygen defects. The study also demonstrated marginal changes in optical bandgap and weak room temperature ferromagnetism in the doped nanoparticles.
SOLID STATE SCIENCES
(2021)
Article
Materials Science, Multidisciplinary
Mohd. Hashim, Nehru Boda, Ateeq Ahmed, S. K. Sharma, D. Ravinder, Edapalli Sumalatha, Anwar Ul-Hamid, Mukhlis M. Ismail, Mohd. Chaman, Sagar E. Shirsath, Ravi Kumar, Shalendra Kumar, Sher Singh Meena, Mohammad Nasir
Summary: In this study, samarium-doped cobalt ferrite nanoparticles were synthesized using citrate gel auto-combustion method and annealed at 500 degrees C for 4 hours. The doping of samarium was found to strongly influence the magnetic properties of the nanoparticles, leading to a decrease in saturation magnetization values. Rietveld analysis confirmed the formation of a single-phase structure in all compositions.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Jitender Kumar, Rajesh Kumar, Mukhtiyar Singh, Shalendra Kumar, Ravi Kumar, Sung Ok Won, Ranjeet Brajpuriya, Sourabh Dwivedi, Ram K. Sharma, Ankush Vij
Summary: The study investigated the structural, reflectance, photoluminescence, and thermoluminescence properties of t-Mg2B2O5 nanostructures synthesized using an optimized combustion method. The direct band gap of 5.23 eV was determined, contrary to previous reports, and first principle calculations confirmed this. The t-Mg2B2O5 nanoparticles exhibited yellow-reddish photoluminescence and UV responsive thermoluminescence, suggesting potential applications in luminescence-based technologies and UV dosimetry. Additionally, the study demonstrated the anti-biofilms activity of Mg2B2O5 nanoparticles against pseudomonas aeruginosa bacterial cells.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Jayanta Bhattacharjee, Sahadeb Ghosh, Preeti Pokhriyal, Rashmi Gangwar, Rajeev Dutt, Archna Sagdeo, Pragya Tiwari, S. D. Singh
Summary: A bandgap bowing parameter of 0.4 +/- 0.2 eV was determined for beta-(AlxGa1-x)(2)O-3 alloys with Al compositions up to 0.35, and an inhomogeneity length scale was estimated for these alloys. The unit cell of these alloys compresses, with lattice parameters varying linearly with Al substitution. These results offer insights into bandgap engineering and alloy disorder in beta-(AlxGa1-x)(2)O-3 alloys, which are important for deep ultraviolet opto-electronic device applications.
Article
Physics, Applied
Sahadeb Ghosh, Madhusmita Baral, Jayanta Bhattacharjee, Rajiv Kamparath, S. D. Singh, Tapas Ganguli
Summary: The study investigated the non-commutativity of band offset in RF magnetron sputter deposited all oxide epitaxial alpha-Cr2O3/beta-Ga2O3 heterojunction, determining valence and conduction band offsets using the Kraut's method. The results showed that the heterojunction did not follow band commutativity and had lower band offset values compared to previous reports, indicating its potential for lower turn on voltage in electron and hole confinement.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Physics, Applied
Sahadeb Ghosh, Mangla Nand, Rajiv Kamparath, Mukul Gupta, D. M. Phase, S. N. Jha, S. D. Singh, Tapas Ganguli
Summary: In this study, oriented thin films of beta-(Ga1-x Fe(x))(2)O-3 were successfully deposited using radio frequency magnetron sputtering on different substrates. The influence of substituted Fe ions on the electronic structure of β-Ga2O3 films was investigated using resonant photoelectron spectroscopy. It was found that Fe substitution altered the band structure of β-Ga2O3, transforming it from a band-like system to a charge-transfer system.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Physics, Applied
Jayanta Bhattacharjee, Archna Sagdeo, S. D. Singh
Summary: By studying β-(AlxGa1-x)(2)O-3 alloys, it was found that the proportion of Al atoms occupying octahedral atomic sites increases with the increase of Al composition, even though these sites are not fully occupied even at an Al composition of 90%. The lattice parameters and bandgap of the alloy show a linear relationship with Al composition, but a change in slope is observed at an Al composition of approximately 50%. Lattice distortion and significant change in bond angles are observed for Al composition exceeding 50%. These findings provide valuable insights into the physical properties of β-(AlxGa1-x)(2)O-3 alloys.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
Geetanjali Vashisht, S. Porwal, S. Haldar, V. K. Dixit
Summary: The study investigated the impact of interface defect states on the recombination and transport properties of charges in asymmetric modulation-doped InGaAs/GaAs quantum wells. It was found that the localization of charge carriers at the interfaces reduced the net electric field, but this effect could be suppressed by the application of a magnetic field, leading to an increase in luminescence and photoconductivity signals. The research suggests that a magnetic field-driven diamagnetic-Landau shift can be used to estimate fundamental parameters of charge carriers in the presence of large interface defect states, benefiting the development of high mobility optoelectronic and spin photonic devices in the field of nano-technology.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Engineering, Chemical
Amarjit Singh, Harish Singh Dhami, Manoj Kumar Sinha, Ravi Kumar
Summary: This article presents a detailed study of the mineralogy, micromeritics, and rheology of various materials, including powders and metal chips. The density and morphology of the particles were found to greatly influence their properties. The study also suggests that waste metallic chips can be recycled through powder metallurgy, saving time compared to ball milling.
Article
Engineering, Electrical & Electronic
Kapil Dev Singh, Dinesh Kumar Shukla, Ravi Kumar
Summary: By utilizing x-ray absorption near-edge spectroscopy (XANES) measurements, we investigated the electronic structure of perovskite-type RCrO3 (R = La, Nd, Eu, Gd, Dy, and Y) compounds. The results showed significant differences in the framework of the metal-oxygen hybridization caused by different rare earth elements (R). The dominant role of Cr3+ was found in all these perovskite-type RCrO3 samples, except for EuCrO3 where Cr existed in a mixed-valence state of +3 and +4. The ligand field-splitting values increased consistently with decreasing rare-earth (R) cationic radii, except for an anomaly in the case of Eu.
JOURNAL OF ELECTRONIC MATERIALS
(2022)
Article
Physics, Condensed Matter
Jayanta Bhattacharjee, S. D. Singh
Summary: In this study, electron-phonon interactions in β-Ga2O3 were investigated by studying the temperature dependent photoluminescence of the red emission line. The observed emission was determined to be excitonic recombination at low temperatures. Different phonon modes were found to interact with different emission lines. In the low temperature region, carrier transfer between emission lines was observed.
SOLID STATE COMMUNICATIONS
(2022)
Correction
Physics, Applied
Jayanta Bhattacharjee, Archna Sagdeo, S. D. Singh
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
Jayanta Bhattacharjee, S. D. Singh
Summary: Raman spectroscopy is used to investigate the phonon mode behavior of a beta-(AlxGa1-x)(2)O-3 alloy with Al compositions up to x=0.474. The alloy exhibits a mixed-mode behavior, with low frequency modes showing monotonic behavior and high frequency modes displaying one-mode behavior. Medium frequency modes show sudden changes and two-mode behavior with Al substitution. The existence of two sublattices is supported by the preferential occupation of Al atoms. These findings provide insight into the phonon mode behavior of beta-(AlxGa1-x)(2)O-3 alloys and their physical properties.
APPLIED PHYSICS LETTERS
(2023)
