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Aloke Kanjilal

Bio: Aloke Kanjilal is an academic researcher from Shiv Nadar University. The author has contributed to research in topics: X-ray photoelectron spectroscopy & Ion implantation. The author has an hindex of 21, co-authored 111 publications receiving 1377 citations. Previous affiliations of Aloke Kanjilal include Indian Institutes of Technology & Helmholtz-Zentrum Dresden-Rossendorf.


Papers
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TL;DR: A sheet of spherical, well-separated, crystalline Ge nanodots embedded in SiO2 on top of a p-(001)Si wafer was fabricated by molecular beam epitaxy (MBE) combined with rapid thermal processing and characterized structurally and electrically as mentioned in this paper.
Abstract: A sheet of spherical, well-separated, crystalline Ge nanodots embedded in SiO2 on top of a p-(001)Si wafer was fabricated by molecular beam epitaxy (MBE) combined with rapid thermal processing and characterized structurally and electrically. The average size of the Ge nanodots was estimated to be 4.5 nm with an average aerial density of 3×1011 cm−2, situated at 4.4 nm in average away from the Si/SiO2 interface. Significant charge storage effects were observed through capacitance–voltage measurements of metal–oxide–semiconductor capacitors.

116 citations

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TL;DR: In this article, the structure and size of PbS nanoparticles were characterized by X-ray diffraction and transmission electron microscopy (TEM) respectively, and decreases in dc-conductivity, Hall mobility and carrier concentration with reducing grain size were also examined.

83 citations

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TL;DR: This model provides a unified explanation for the work-function changes at both junctions and enables us to determine the benzenethiolate orientation as a function of coverage.
Abstract: The energy level alignment at the metal-organic and organic-organic interfaces of the Cu(100)/ benzenethiolate/pentacene heterostructure is studied by photoemission spectroscopy and discussed theoretically using a model that includes, in a consistent way, charge transfer, Pauli repulsion, intrinsic molecular dipoles, and interface screening as a function of coverage. Despite the different nature of the two interfaces, our model provides a unified explanation for the work-function changes at both junctions and enables us to determine the benzenethiolate orientation as a function of coverage.

66 citations

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TL;DR: In this paper, a vertically correlated submonolayer (VCSML) InAs/GaAs quantum-dot (QD) heterostructure was studied using transmission electron microscopy, high-resolution x-ray diffraction (HRXRD) and polarization-dependent photoluminescence.
Abstract: A vertically correlated submonolayer (VCSML) InAs/GaAs quantum-dot (QD) heterostructure was studied using transmission electron microscopy, high-resolution x-ray diffraction (HRXRD) and polarization-dependent photoluminescence. The HRXRD (004) rocking curve was simulated using the Tagaki–Taupin equations. Excellent agreement between the experimental curve and the simulation is achieved assuming that indium-rich VCSML QDs are embedded in a quantum well (QW) with lower indium content and an observed QD coverage of 10%. In the VCSML QDs, the vertical lattice mismatch of the InAs monolayer with respect to GaAs is around 1.4%, while the lattice mismatch in the QW is negligible. The photoluminescence is transverse magnetic—polarized in the edge geometry.

66 citations

Journal ArticleDOI
TL;DR: In this article, structural and optical properties of Mn-doped CdS thin films prepared by 190 keV Mn-ion implantation at different temperatures were investigated and shown to exhibit a new band in their photoluminescence spectra at 2.22 eV which originates from the d-d transition of tetrahedrally coordinated Mn2+ ions.
Abstract: We report on structural and optical properties of Mn-doped CdS thin films prepared by 190 keV Mn-ion implantation at different temperatures. Mn-ion implantation in the fluence range of 1×1013–1×1016 ions cm−2 does not lead to the formation of any secondary phase. However, it induces structural disorder, causing a decrease in the optical band gap. This is addressed on the basis of band tailing due to creation of localized energy states and Urbach energy calculations. Mn-doped samples exhibit a new band in their photoluminescence spectra at 2.22 eV, which originates from the d-d (T41→A61) transition of tetrahedrally coordinated Mn2+ ions.

53 citations


Cited by
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TL;DR: In this article, the authors review recent progress in the understanding of effects of irradiation on various zero-dimensional and one-dimensional nanoscale systems, such as semiconductor and metal nanoclusters and nanowires, nanotubes, and fullerenes.
Abstract: A common misconception is that the irradiation of solids with energetic electrons and ions has exclusively detrimental effects on the properties of target materials. In addition to the well-known cases of doping of bulk semiconductors and ion beam nitriding of steels, recent experiments show that irradiation can also have beneficial effects on nanostructured systems. Electron or ion beams may serve as tools to synthesize nanoclusters and nanowires, change their morphology in a controllable manner, and tailor their mechanical, electronic, and even magnetic properties. Harnessing irradiation as a tool for modifying material properties at the nanoscale requires having the full microscopic picture of defect production and annealing in nanotargets. In this article, we review recent progress in the understanding of effects of irradiation on various zero-dimensional and one-dimensional nanoscale systems, such as semiconductor and metal nanoclusters and nanowires, nanotubes, and fullerenes. We also consider the t...

905 citations

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TL;DR: The characterization techniques that provide information used to enhance the understanding of structure/property relationships in semiconducting polymers are reviewed.
Abstract: The performance of semiconducting polymers has been steadily increasing in the last 20 years. Improved control over the microstructure of these materials and a deeper understanding of how the microstructure affects charge transport are partially responsible for such trend. The development and widespread use of techniques that allow to characterize the microstructure of semiconducting polymers is therefore instrumental for the advance of these materials. This article is a review of the characterization techniques that provide information used to enhance the understanding of structure/property relationships in semiconducting polymers. In particular, the applications of optical and X-ray spectroscopy, X-ray diffraction, and scanning probe techniques in this context are described.

476 citations

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TL;DR: Greiner et al. as mentioned in this paper provided a rational guide to process engineers in selecting the best suitable electrode/oxide structures for a targeted applications, which can be used as a buffer layer to modify the electrode work function.
Abstract: Thin-film metal oxides are among the key materials used in organic semiconductor devices. As there are no intrinsic charge carriers in a typical organic semiconductor, all charges in the device must be injected from electrode/organic interfaces, whose energetic structure consequentially dictates the performance of devices. The energy barrier at the interface depends critically on the work function of the electrode. For this reason, various types of thin-film metal oxides can be used as a buffer layer to modify the electrode work function. This paper provides a review on recent progress in metal oxide/organic interface energetics, oxide valence structure and work function, as well as the impact of defects and interfacial reactions on oxide work functions. This review provides a rational guide to process engineers in selecting the best suitable electrode/oxide structures for a targeted applications. Organic semiconductors offer an attractive alternative to the traditional, silicon-based components of electronic devices. Cheaper to produce and more sustainable, they can also introduce different attributes, such as flexibility, to these devices. However, as organic materials do not typically possess intrinsic charge carriers — electrons or holes — all charges in the device must originate from the electrode and pass through the electrode-organic material interface, a process hindered by an energy barrier. Mark Greiner and Zheng-Hong Lu review recent achievements in a versatile class of buffer layer — thin films of transition metal oxides — that can be positioned between the two materials to reduce the energy barrier that limits charge injection. The researchers discuss how to select the most suitable metal oxide for a specific purpose, and then tune the thin film's properties by adjusting the thickness of the metal oxide layer, the oxidation state of its cations and the concentration of its defects. Over the last decade, metal oxides have proven to be important materials for organic electronics. Oxides are often used as charge-injection and charge-selective interlayers to engineer the electrical resistance at electrode/organic interfaces in organic devices. An oxide’s behavior as an interlayer depends strongly on the oxide’s electronic properties—such as its band structure and work function. The numerous degrees of freedom in an oxide’s electronic properties allow these characteristics to be easily modified. The present review outlines the use of metal oxides in organic electronics, and discusses the factors that affect the oxide’s properties that are relevant to oxide/organic interfaces.

332 citations

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TL;DR: In this article, a review is presented on the status of synthesizing thin films of metal chalcogenide and metal oxides by CBD and SILAR, and properties and applications of the thin films are also summarized.

307 citations

Journal ArticleDOI
TL;DR: This review highlights different strategies for effectively introducing oxygen vacancies in titanium oxide-based nanomaterials, as well as a discussion on the positions of oxygen vacancies inside the TiO2 band gap based on theoretical calculations.
Abstract: TiO2 and other titanium oxide-based nanomaterials have drawn immense attention from researchers in different scientific domains due to their fascinating multifunctional properties, relative abundance, environmental friendliness, and bio-compatibility. However, the physical and chemical properties of titanium oxide-based nanomaterials are found to be explicitly dependent on the presence of various crystal defects. Oxygen vacancies are the most common among them and have always been the subject of both theoretical and experimental research as they play a crucial role in tuning the inherent properties of titanium oxides. This review highlights different strategies for effectively introducing oxygen vacancies in titanium oxide-based nanomaterials, as well as a discussion on the positions of oxygen vacancies inside the TiO2 band gap based on theoretical calculations. Additionally, a detailed review of different experimental techniques that are extensively used for identifying oxygen vacancies in TiO2 nanostructures is also presented.

258 citations