The photodetector of Ge nanocrystals/Si for 1.55μm operation deposited by pulsed laser deposition

Ma, Xiang; Yuan, Baohe; Yan, Zhijun

doi:10.1016/j.optcom.2005.10.037

Cited by 11 publications

(6 citation statements)

References 18 publications

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“…Although silicon is the leader of the group 14 nanocrystal congeners, germanium (Ge) offers unique opportunities that are actively being pursued, especially for charge storage and infrared optical and optoelectronic applications. − Similarly to most semiconductor nanocrystals, focus has primarily been on Ge quantum dots, where size-dependent optical and electronic properties have been investigated mostly for optoelectronic or in vivo biological imaging applications. , However, what is perhaps an overlooked “nano advantage” is the solution-processability of colloidally stable nanomaterials for the production of structures which retain bulk properties, offering attractive alternatives to typical top-down fabrication techniques. Inexpensive, scalable, using nontoxic and easy to handle precursors, and requiring minimal infrastructure, spin-coating, dip-coating, and spray-coating, to name but a new, are certainly appealing thin film deposition methods, as long as the properties of the final material are suitable for the desired application.…”

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confidence: 99%

Colloidally Stable Germanium Nanocrystals for Photonic Applications

et al. 2010

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We report the development of a straightforward synthesis for colloidally stable germanium nanocrystals for use as a solution-processable precursor for the bottom-up fabrication of functional thin films. SiO(2)-embedded germanium nanocrystals are produced by the reductive thermal processing of sol-gel glasses derived from mixtures of tetraethoxyorthogermanate (TEOG) and tetraethoxyorthosilicate (TEOS), and free-standing germanium nanocrystals are liberated from the encapsulating silicon dioxide through sequential chemical etching. The applicability of these germanium nanocrystals as a solution-processable thin film precursor is demonstrated by the fabrication of high refractive index thin films.

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confidence: 99%

Colloidally Stable Germanium Nanocrystals for Photonic Applications

et al. 2010

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“…In this model, light of 1.55µm wavelength from a 200µw LED is launched in the silica nanowire [8]. The photodetector used in this model produces a difference in photocurrent of about 1µA before and after exposure of silica nanowire to propane gas, for 650nm-950nm diameters [9].…”

Section: Simulation and Resultsmentioning

confidence: 99%

Modeling of Evanescent Field Propane Gas Sensor Using Silane-Treated Single Mode Silica Nanowire

Kulkarni¹,

Patrikar

2012

2012 Symposium on Photonics and Optoelectronics

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In the present work, two types of miniature propane gas sensors using silica nanowire are modeled and simulated. Silica nanowires leave large amount of guided field outside the core as evanescent field, which is sensitive to cladding refractive index and hence utilized for sensing purpose. In this paper, two types of sensors are investigated from silica nanowire waveguiding properties In both models, silica nanowire initially has air as cladding which changes to gaseous layer of propane when exposed to the propane gas. Layer formation is achieved by adsorption. Silica nanowire treated with methyl-hydrogen silane is used in these models to increase adsorption tendency of propane on the silica nanowire surface. In the first model, MachZehnder interferometer is used for measurements. In the second model, measurements are carried out with photodetectorcomparator circuit. High sensitivity conditions are obtained in both models. Simulation of the models show that using nanowires diameters of 350nm-750nm, high sensitivity can be achieved, even with small sensing length in the first model, whereas in the second model, high sensitivity can be achieved using 650nm-950nm nanowire diameters. These sensors can be helpful in early detection of hazardous liquefied petroleum gas leakage.Keywords-Silica nanowire, propane gas sensor, evanescent field sensor, propane gas adsorption, silane treated silica surface.

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“…24 a Due to the fact of smaller gap, higher carrier mobility, and lighter effective mass, Ge nanocrystals can be used in charge storage, 25 infrared optics 26 and optoelectronics. 27 Especially, Ge is a candidate of green environment material, 28,29 which is non toxic compared with nanocrystals containing Pb, Cd, and Hg.…”

Section: Introductionmentioning

confidence: 99%

Temperature effect on the structural stabilities and electronic properties of X22H28 (X=C, Si and Ge) nanocrystals: A first-principles study

et al. 2016

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Based on ab initio molecular dynamic simulations, we have theoretically investigated the structural stabilities and electronic properties of X22H28 (X=C, Si, and Ge) nanocrystals, as a function of temperature with consideration of vibrational entropy effects. To compare the relative stabilities of X22H28 isomers, the vibration free energies are obtained according to the calculated phonon spectrum, where the typical modes are shown to be dominant to the structural stabilities. In addition, there is a significant gap reduction as the temperature increases from 0 K to 300 K, where the decrements are 0.2 /0.5 /0.6eV for C/Si/Ge nanocrystals, respectively. The dependence of energy gap on the variance of bond length is also analyzed according to the corresponding atomic attributions to the HOMO and LUMO levels.

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The photodetector of Ge nanocrystals/Si for 1.55μm operation deposited by pulsed laser deposition

Cited by 11 publications

References 18 publications

Colloidally Stable Germanium Nanocrystals for Photonic Applications

Colloidally Stable Germanium Nanocrystals for Photonic Applications

Modeling of Evanescent Field Propane Gas Sensor Using Silane-Treated Single Mode Silica Nanowire

Temperature effect on the structural stabilities and electronic properties of X22H28 (X=C, Si and Ge) nanocrystals: A first-principles study

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