scholarly journals Estimation of Thin-Film Contribution in Phase Change Calculations Involving Cryogenic Propellants

2019 ◽  
Vol 56 (5) ◽  
pp. 1646-1650 ◽  
Author(s):  
Praveen Srikanth ◽  
Steven H. Collicott
Keyword(s):  
Thin Film ◽  
Phase Change ◽  
Cryogenic Propellants

The effect of an aluminum heat-sink layer on the laser-induced amorphization of SiOx/TeGeSn/SiOx phase-change recording films

1989 ◽  
Vol 47 ◽  
pp. 574-575
Author(s):  
Matthew R. Libera ◽  
Martin Chen
Keyword(s):  
Thin Film ◽  
Phase Change ◽  
Heat Sink ◽  
Multilayer Film ◽  
Glassy Phase ◽  
Film Structure ◽  
Glass Forming ◽  
Active Storage ◽  
Dielectric Layers ◽  
Amorphous States

Phase-change erasable optical storage is based on the ability to switch a micron-sized region of a thin film between the crystalline and amorphous states using a diffraction-limited laser as a heat source. A bit of information can be represented as an amorphous spot on a crystalline background, and the two states can be optically identified by their different reflectivities. In a typical multilayer thin-film structure the active (storage) layer is sandwiched between one or more dielectric layers. The dielectric layers provide physical containment and act as a heat sink. A viable phase-change medium must be able to quench to the glassy phase after melting, and this requires proper tailoring of the thermal properties of the multilayer film. The present research studies one particular multilayer structure and shows the effect of an additional aluminum layer on the glass-forming ability.

Electron Microscopy Study on Amorphous Ge-Sb-Te Thin Film for Phase Change Optical Recording

2003 ◽  
Vol 42 (Part 2, No. 10A) ◽  
pp. L1158-L1160 ◽  
Author(s):  
Muneyuki Naito ◽  
Manabu Ishimaru ◽  
Yoshihiko Hirotsu ◽  
Masaki Takashima
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Phase Change ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Optical Recording

Atomistic and macroscopic characterization of nanoscale thin film liquid-vapor phase change phenomena

2021 ◽  
Vol 170 ◽  
pp. 107159
Author(s):  
Md Muntasir Alam ◽  
Md Shajedul Hoque Thakur ◽  
Mahmudul Islam ◽  
Mohammad Nasim Hasan ◽  
Yuichi Mitsutake ◽  
...  
Keyword(s):  
Thin Film ◽  
Phase Change ◽  
Vapor Phase ◽  
Nanoscale Thin Film ◽  
Phase Change Phenomena ◽  
Liquid Vapor

scholarly journals All-optical dynamic tuning of local excitonic emission of monolayer MoS2 by integration with Ge2Sb2Te5

Nanophotonics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 2351-2359
Author(s):  
Hao Ouyang ◽  
Haitao Chen ◽  
Yuxiang Tang ◽  
Jun Zhang ◽  
Chenxi Zhang ◽  
...  
Keyword(s):  
Thin Film ◽  
Phase Change ◽  
Optical Networks ◽  
Dominant Role ◽  
Laser Pulses ◽  
Coulomb Interactions ◽  
Optical Modulators ◽  
Dynamic Tuning ◽  
All Optical ◽  
Excitonic Emission

AbstractStrong quantum confinement and coulomb interactions induce tightly bound quasiparticles such as excitons and trions in an atomically thin layer of transitional metal dichalcogenides (TMDs), which play a dominant role in determining their intriguing optoelectronic properties. Thus, controlling the excitonic properties is essential for the applications of TMD-based devices. Here, we demonstrate the all-optical tuning of the local excitonic emission from a monolayer MoS2 hybridized with phase-change material Ge2Sb2Te5 (GST) thin film. By applying pulsed laser with different power on the MoS2/GST heterostructure, the peak energies of the excitonic emission of MoS2 can be tuned up to 40 meV, and the exciton/trion intensity ratio can be tuned by at least one order of magnitude. Raman spectra and transient pump-probe measurements show that the tunability originated from the laser-induced phase change of the GST thin film with charge transferring from GST to the monolayer MoS2. The dynamic tuning of the excitonic emission was all done with localized laser pulses and could be scaled readily, which pave a new way of controlling the excitonic emission in TMDs. Our findings could be potentially used as all-optical modulators or switches in future optical networks.

scholarly journals Capillary-Limited Evaporation From Well-Defined Microstructured Surfaces

2013 ◽  
Author(s):  
Solomon Adera ◽  
Rishi Raj ◽  
Evelyn N. Wang
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Heat Flux ◽  
Phase Change ◽  
Thermal Management ◽  
Latent Heat ◽  
Thin Film Evaporation ◽  
Film Evaporation ◽  
Microstructured Surfaces ◽  
Latent Heat Of Vaporization

Thermal management is increasingly becoming a bottleneck for a variety of high power density applications such as integrated circuits, solar cells, microprocessors, and energy conversion devices. The performance and reliability of these devices are usually limited by the rate at which heat can be removed from the device footprint, which averages well above 100 W/cm2 (locally this heat flux can exceed 1000 W/cm2). State-of-the-art air cooling strategies which utilize the sensible heat are insufficient at these large heat fluxes. As a result, novel thermal management solutions such as via thin-film evaporation that utilize the latent heat of vaporization of a fluid are needed. The high latent heat of vaporization associated with typical liquid-vapor phase change phenomena allows significant heat transfer with small temperature rise. In this work, we demonstrate a promising thermal management approach where square arrays of cylindrical micropillar arrays are used for thin-film evaporation. The microstructures control the liquid film thickness and the associated thermal resistance in addition to maintaining a continuous liquid supply via the capillary pumping mechanism. When the capillary-induced liquid supply mechanism cannot deliver sufficient liquid for phase change heat transfer, the critical heat flux is reached and dryout occurs. This capillary limitation on thin-film evaporation was experimentally investigated by fabricating well-defined silicon micropillar arrays using standard contact photolithography and deep reactive ion etching. A thin film resistive heater and thermal sensors were integrated on the back side of the test sample using e-beam evaporation and acetone lift-off. The experiments were carried out in a controlled environmental chamber maintained at the water saturation pressure of ≈3.5 kPa and ≈25 °C. We demonstrated significantly higher heat dissipation capability in excess of 100 W/cm2. These preliminary results suggest the potential of thin-film evaporation from microstructured surfaces for advanced thermal management applications.

scholarly journals Holographic image generation with a thin-film resonance caused by chalcogenide phase-change material

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Seung-Yeol Lee ◽  
Yong-Hae Kim ◽  
Seong-M. Cho ◽  
Gi Heon Kim ◽  
Tae-Youb Kim ◽  
...  
Keyword(s):  
Thin Film ◽  
Phase Change ◽  
Phase Change Material ◽  
Image Generation ◽  
Holographic Image ◽  
Change Material
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