Article
Chemistry, Multidisciplinary
Varun Harbola, Yu-Jung Wu, Hongguang Wang, Sander Smink, Sarah C. Parks, Peter A. van Aken, Jochen Mannhart
Summary: A novel route is presented for fabricating nanocrystalline oxide structures via the self-assembly process of ultrathin membranes composed of the desired oxide. The self-assembly of nanocrystalline structures is driven by the dewetting of oxide membranes once they are transferred onto sapphire surfaces. The resulting nanostructures have highly anisotropic shapes determined by the crystal lattice of the transferred membrane, and exhibit exceptional quality with a pristine crystal structure and uniform stoichiometry.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Ilia Smirnov, Zbigniew Kaszkur, Armin Hoell
Summary: The appearance of twin/stacking faults in nanoparticles affects their catalytic, optical, and electrical properties. However, there is a lack of experimental tools for characterizing these defects numerically, leading to poor understanding of structure-property correlations. In this study, we explored the twinning effect on XRD pattern and developed a new approach based on the mutual orientation of periodic fcc segments. By performing computational simulations, we found a correlation between the number of domains and the height ratio of 220 to 111 diffraction peaks. Our XRD analysis of Au and AuPt samples, compared with TEM and SAXS analyses, demonstrates the potential of our multidomain XRD method in studying structure-property correlations in nanomaterials.
Article
Chemistry, Multidisciplinary
Ji Qi, Yuan Zhang, Huan Liu, Hang Xu, Chen Wang, Linglong Hu, Ming Feng, Weiming Lu
Summary: In this study, the effects of strain on the oxygen evolution reaction (OER) performance were investigated using different types of strain. It was found that the strain exhibited different trends in rigid and flexible materials, which can be explained by the difference in oxygen activation energy in lattice fields.
Article
Multidisciplinary Sciences
Ovidiu Cojocaru, Ana-Maria Lepadatu, George Alexandru Nemnes, Toma Stoica, Magdalena Lidia Ciurea
Summary: A detailed study on the bandgap dependence of spherical Ge-rich GexSi1-x nanocrystals was conducted using atomistic density functional theory calculations. The results show a composition invariance of the bandgap diameter dependence, with the bandgap of NCs being well described by a power function for a certain diameter range. H-passivation of the NC surface helps accurately determine the NC bandgap by excluding surface states near the band edges.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Physical
Rachel C. Barbieri, Kai Ding, Umit Ozgur, Indika U. Arachchige
Summary: Ge1-xSnx nanocrystals are direct-gap semiconductors with tunable size and composition, showing enhanced optical properties and conductivity compared to pure Ge nanocrystals. By replacing insulating ligands with molecular metal chalcogenides, solution-processed conductive thin films can be produced, leading to significantly increased electrical conductivity. The alloying of Ge and Sn results in blue-shifted energy gaps and increased conductivity, making these nanocrystals promising for various optoelectronic applications.
CHEMISTRY OF MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Tadeas Hanus, Bouraoui Ilahi, Alexandre Chapotot, Hubert Pelletier, Jinyoun Cho, Kristof Dessein, Abderraouf Boucherif
Summary: Semiconductor-based freestanding membranes (FSM) are a highly promising area of research due to their lightweight and flexibility. However, the production of high-quality, single-crystalline FSM from elemental materials such as germanium (Ge) is challenging.
MATERIALS TODAY ADVANCES
(2023)
Article
Optics
Yongduck Jung, Daniel Burt, Lin Zhang, Youngmin Kim, Hyo-Jun Joo, Melvina Chen, Simone Assali, Oussama Moutanabbir, Chuan Seng Tan, Donguk Nam
Summary: This study demonstrates the significant improvement in the lasing threshold of GeSn lasers by reducing the defect density in GeSn-on-insulator substrate, leading to enhanced spontaneous emission and lower threshold.
PHOTONICS RESEARCH
(2022)
Article
Physics, Applied
Kazunori Matsuda, Masashi Yamamoto, Michio Mikawa, Shiro Nagaoka, Nobuya Mori, Kazuo Tsutsui
Summary: The effects of hydrogen radical treatment on the piezoresistance coefficients of germanium under uniaxial stress were investigated. It was found that the treatment caused a dramatic change in the gauge factor and majority carrier of non-doped germanium. The results suggest that the piezoresistance coefficients of germanium are influenced by vacancy-related levels around the midgap, which act as donors or acceptors depending on the Fermi level and are passivated by hydrogen radicals.
APPLIED PHYSICS EXPRESS
(2023)
Article
Chemistry, Multidisciplinary
Ricci Erlandsen, Rasmus Tindal Dahm, Felix Trier, Mario Scuderi, Emiliano Di Gennaro, Alessia Sambri, Charline Kaisa Reffeldt Kirchert, Nini Pryds, Fabio Miletto Granozio, Thomas Sand Jespersen
Summary: This study reports the fabrication of freestanding oxide membranes with metallic conductivity and superconducting phases, which can be used to form devices on silicon substrates, indicating the potential for integrating oxide nanoelectronics with silicon-based architectures.
Article
Materials Science, Multidisciplinary
Costanza Lucia Manganelli, Michele Virgilio, Michele Montanari, Ignatii Zaitsev, Nicola Andriolli, Stefano Faralli, Stefano Tirelli, Fabio Dagnano, Wolfgang Matthias Klesse, Davide Spirito
Summary: The influence of thermomechanical effects on the optical properties of germanium microstructures was studied using finite element method calculations. The study included evaluating mechanical deformations induced by a silicon nitride stressor layer on Ge micropillars, confirming simulated strain maps with experimental maps obtained by Raman spectroscopy, and quantifying the joint effect of temperature and strain on the fundamental bandgap.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2021)
Article
Nanoscience & Nanotechnology
Yuxin Cheng, Yaojin Li, Guohua Dong, Bin Peng, Ziyao Zhou, Ming Liu
Summary: The key concept in flexible/freestanding spintronics involves effectively controlling ultra-thin film magnetism while ensuring that functional properties are not compromised when gating methods are applied. By coupling the freestanding characteristic with important magnetic properties, it is possible to expand the storage area of freestanding spintronics. This work demonstrates the feasibility of tunable flexible spintronics through freestanding mechanisms and showcases the promising future of freestanding spintronics.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Deependra Parmar, Adam J. Mallette, Taimin Yang, Xiaodong Zou, Jeffrey D. Rimer
Summary: Adding germanium oxide to the zeolite growth mixture directs the formation of zeolites with ultrasmall dimensions. This method not only enhances the performance of zeolite catalysts, but also has the potential to reduce mass-transport limitations in various applications.
ADVANCED MATERIALS
(2022)
Article
Mechanics
Yingzhuo Lun, Shaoqing Xu, Xueyun Wang, Jiawang Hong
Summary: The use of freestanding oxide films allows for large strain gradients in dielectrics to enhance the flexoelectricity. By changing the interfacial mismatch strain, film thickness, and the thickness ratio of the membrane to substrate layer, the strain gradient can reach as large as 107 m-1. Different self-rolling morphologies with varying flexoelectric polarization can be obtained by adjusting the anisotropic interfacial mismatch strain and released direction. Unlike the neutralized piezoelectric response, the flexoelectric polarization in self-rolling films is uniform across the thickness and significantly enhanced as the film thickness decreases. The effective flexo-electric polarization is six times larger than the piezoelectric one. This research opens up new possibilities for utilizing flexoelectricity in nanoscale self-rolling film-based devices and applications.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2023)
Article
Multidisciplinary Sciences
Giichiro Uchida, Kenta Nagai, Yuma Habu, Junki Hayashi, Yumiko Ikebe, Mineo Hiramatsu, Ryota Narishige, Naho Itagaki, Masaharu Shiratani, Yuichi Setsuhara
Summary: In this study, nanostructured Ge and GeSn films were fabricated using He radio-frequency magnetron plasma sputtering deposition. The addition of Sn improved the capacity and cycling performance of lithium-ion batteries with Ge and GeSn anodes.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Yechao Ling, Xiao Yu, Shijun Yuan, Anpeng He, Zhida Han, Jun Du, Qi Fan, Shicheng Yan, Qingyu Xu
Summary: Freestanding thin films of functional materials can have their properties tuned via strain and strain gradients, expanding their range of applications. In this study, a systematic approach was used to fabricate freestanding CrMnFeCoNi high-entropy alloy thin films and it was found that the strain gradients in these films can induce structural phase transitions and changes in magnetic properties.
Article
Chemistry, Multidisciplinary
Ravi K. Biroju, Bhanu Chandra Marepally, Pariksha Malik, Soumen Dhara, Saravanan Gengan, Dipak Maity, Tharangattu N. Narayanan, Pravat K. Giri
Summary: In this study, defective graphene and transition metal (TM) hybrids were investigated for their plasmonic effects in UV-vis-NIR spectrum. Extensive analysis using Raman spectroscopy, transmission electron microscopy, and absorption measurements was conducted. The findings revealed the interaction between plasmonic nanoparticles and graphene and the charge transfer process. The defective graphene and Au hybrids showed significant Raman enhancement with practical applications.
Article
Nanoscience & Nanotechnology
Tadasha Jena, Md Tarik Hossain, Upasana Nath, Manabendra Sarma, Hiroshi Sugimoto, Minoru Fujii, P. K. Giri
Summary: In this study, it is discovered that intrinsic defects in 2D palladium diselenide (PdSe2) dendrites can serve as hotspots for high surface-enhanced Raman spectroscopy (SERS) enhancement. The vacancy-rich dendritic PdSe2 demonstrates a SERS enhancement factor >10(5) and can detect RhB at a concentration down to 10(-8) M. The topological defects and edge construction in PdSe2 dendrites contribute to the high enhancement in the SERS signal. This research bridges the gap between conventional plasmonic SERS substrates and plasmon-free SERS substrates.
NPJ 2D MATERIALS AND APPLICATIONS
(2023)
Review
Chemistry, Analytical
Abdul Kaium Mia, M. Meyyappan, P. K. Giri
Summary: Since the discovery of graphene in 2004, there has been a significant increase in research on two-dimensional (2D) materials. Transition metal dichalcogenides (TMDs) are a class of 2D materials with unique optical and electronic properties that make them suitable for various applications. In this review, the use of TMDs in biosensors for real-time detection of biomarkers and the potential for healthcare devices are discussed.
Review
Materials Science, Multidisciplinary
Joydip Ghosh, Sumaiya Parveen, P. J. Sellin, P. K. Giri
Summary: Layered metal halide perovskites have gained significant attention due to their unique optical and electronic properties. This article reviews the recent progress and opportunities in 2D and quasi-2D perovskites for various applications, including LEDs, lasers, memristors, neuromorphic/synaptic devices, UV-vis photodetection, X-ray detection, scintillators, and photocatalysis. The crystal structure, characteristics, and fundamental properties of 2D layered perovskites are discussed, along with their excellent luminescence properties for light-emitting applications. The exceptional properties of 2D perovskites, such as low leakage current and high stability, make them suitable for memristor devices. The article also highlights the outstanding performance of 2D perovskites in UV-vis photodetection and their potential as superior candidates for X-ray detection and scintillation.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Chemistry, Physical
Souradip Ganguly, Sumana Paul, Deepak Khurana, Tuhin Suvra Khan, P. K. Giri, Chanchal Loha, Sirshendu Ghosh
Summary: Electrocatalytic hydrogen (H2) generation has been a popular research topic in the past decade because H2 is a clean and non-polluting energy source. Substituting the oxygen evolution reaction (OER) with easily oxidizable substrate oxidation reaction can result in H2 production at a lower energy cost. Ni1-xCoxSe electrocatalyst has been developed for efficient conversion of alcohol molecules to value-added commodity chemicals.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Chemistry, Physical
Ravinder Chahal, Abhilasha Bora, P. K. Giri
Summary: This study demonstrates the growth of highly crystalline and uniform Cs2AgBiBr6 thin films via chemical vapor deposition (CVD). The thin films exhibit high structural and compositional uniformity with excellent thermal stability and optoelectronic performance. The substrate-dependent growth aids in studying the induced lattice strain, while a detailed analysis of electron-phonon and phonon-phonon interactions was conducted in the Cs2AgBiBr6 double perovskite system. Additionally, the CVD-grown Cs2AgBiBr6 film on a SiO2 substrate showed fast photoresponse when used as a photodetector. The results provide insights for the development of high-performance optoelectronic devices based on lead-free inorganic double perovskites.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Md Tarik Hossain, Larionette P. L. Mawlong, Tadasha Jena, Abhilasha Bora, Upasana Nath, Manabendra Sarma, P. K. Giri
Summary: Interlayer charge transfer based on band alignment is important for various optoelectronic applications. This study investigates the interlayer coupling and charge transfer in a heterostructure composed of van der Waals and non-van der Waals materials. It is found that significant interlayer charge transfer occurs due to favorable band alignment. These findings have implications for understanding the interaction between different types of 2D heterostructures and their potential applications in optoelectronics.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Ramesh Ghosh, Joydip Ghosh, P. K. Giri, Puspendu Guha, Gyu-Chul Yi
Summary: A facile growth of hybrid perovskite nanoparticles (NPs) has been demonstrated on mesoporous, high-aspect ratio, morphology-controlled Si nanorod (NR) arrays. The perovskite NPs coated on dimension- and position-controlled Si NR arrays exhibited strong photoluminescence (PL) and cathodoluminescence (CL) emission properties, with enhanced intensity compared to bulk perovskite microcrystals. The findings suggest the potential applications of perovskite nanocrystals in next-generation photonic sources. Evaluation: 8/10
MATERIALS TODAY CHEMISTRY
(2023)
Article
Engineering, Electrical & Electronic
Rakesh K. Prasad, Koushik Ghosh, Pravat K. Giri, Dai-Sik Kim, Dilip K. Singh
Summary: Future generation technologies require high efficiency photodetectors for ultrafast communication and machine vision. Monolayered two-dimensional semiconductor-based photodetectors have the potential to fulfill these requirements. In this paper, a WS2-based photodetector was fabricated with high sensitivity and low incident power density, demonstrating its capability to replace Si-photodetectors with superior performance parameters.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Subhankar Debnath, Koushik Ghosh, M. Meyyappan, P. K. Giri
Summary: A high-performance Si/WS2 quantum dot-based heterostructure photodetector has been fabricated by a simple printing process, exhibiting short electrode gap, high photo-to-dark current ratio, high responsivity, and wide wavelength range. The high-performance photodetection is attributed to the defect-free interface at the heterojunction, enabling efficient charge separation and high photocurrent. Furthermore, the 2D-printed device shows good photodetection even in self-powered conditions.
Article
Chemistry, Multidisciplinary
Sumana Paul, Sanju Nandi, Mandira Das, Abhilasha Bora, Md Tarik Hossain, Subhradip Ghosh, P. K. Giri
Summary: In this study, ultrathin Bi2O2Se quantum dots with small size and strong visible fluorescence were synthesized using a top-down chemical approach. These quantum dots exhibited high optical band gap and fluorescence quantum yield in the green region, and were selective for detecting iron ions over a wide dynamic range with low detection limit. The mechanism of fluorescence and quenching induced by iron ions was investigated, and the synthesis method was proposed for potential applications in heavy metal ion sensing.
Article
Chemistry, Multidisciplinary
Md Tarik Hossain, Tadasha Jena, Upasana Nath, Manabendra Sarma, P. K. Giri
Summary: The success of non-van der Waals two-dimensional bismuth oxyselenide crystals in optoelectronics has opened up opportunities to explore their fundamental properties. However, the origin of photoluminescence and the effect of growth substrates on the structure and optical properties of these crystals remain unclear. This study reveals that the formation of multiple excitons in momentum valleys is responsible for broadband absorption and visible photoluminescence in few-layer thick bismuth oxyselenide. It also demonstrates that different growth substrates introduce strain and doping, thereby modulating the morphology, absorption, and photoluminescence properties.
Article
Materials Science, Multidisciplinary
Md Tarik Hossain, Tadasha Jena, Subhankar Debnath, P. K. Giri
Summary: In this study, ultrathin Bi2O2Se nanostructures were synthesized through a scalable chemical reaction process and their structural and optoelectronic functionalities were modulated through vacuum annealing. It was found that vacuum annealing improved the crystal quality and led to a conversion from negative persistent photoconductivity to positive photoconductivity. The defects in the nanocrystals also played a key role in modulating the wavelength-dependent photoconductivity. The research highlights the importance of vacuum annealing in improving the crystallinity and the practical applications of Bi2O2Se nanostructures in optoelectronics.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Sirsendu Ghosal, Abhilasha Bora, P. K. Giri
Summary: Oxygen vacancy engineering in metal oxide-based semiconductors is an important research area for sensing applications. In this study, we demonstrate that oxygen vacancy engineering in Niobium pentoxide enables ultrahigh SERS sensitivity. Through analysis of experimental data and theoretical calculations, we show that the SERS performance is directly proportional to the oxygen vacancy concentration in the Nb2O5 nanoparticles.
Article
Materials Science, Biomaterials
Abdul Kaium Mia, Abhilasha Bora, Md Tarik Hossain, Swapnil Sinha, P. K. Giri
Summary: In this study, the ultrafast and sensitive detection of Staphylococcus aureus was achieved using a tungsten disulfide quantum dot and bismuth oxyselenide nanosheet hybrid. The detection was based on the unique optical functionalities of these materials, and a specific sequencing single-standard DNA aptamer was used for selective detection. The proposed biosensor showed a linear response and fast response time, and it was successfully tested in human urine samples.
JOURNAL OF MATERIALS CHEMISTRY B
(2023)
