The volume scanner optical performance

2017 ◽  
Author(s):  
Elham Vafa ◽  
John Holdsworth ◽  
Galiya Sharafutdinova ◽  
Stefan Andersson-Engels
Keyword(s):  
Optical Performance

Electro-Optical Performance of OLED with MEH-PPV Fabricated by Solution Process

2019 ◽  
pp. 727
Author(s):  
Seok Je Lee ◽  
Fangnan Yao ◽  
Seung Il Lee ◽  
Cao Jin ◽  
Woo Young Kim ◽  
...  
Keyword(s):  
Solution Process ◽  
Optical Performance

scholarly journals Enhanced Performance and Diffusion Robustness of Phase-Change Metasurfaces via a Hybrid Dielectric/Plasmonic Approach

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 525
Author(s):  
Joe Shields ◽  
Carlota Ruiz de Galarreta ◽  
Jacopo Bertolotti ◽  
C. David Wright
Keyword(s):  
Melting Point ◽  
Phase Change ◽  
Noble Metals ◽  
Phase Change Materials ◽  
High Efficiency ◽  
The Body ◽  
Design Stage ◽  
High Melting ◽  
Optical Performance ◽  
Electrical Conductors

Materials of which the refractive indices can be thermally tuned or switched, such as in chalcogenide phase-change alloys, offer a promising path towards the development of active optical metasurfaces for the control of the amplitude, phase, and polarization of light. However, for phase-change metasurfaces to be able to provide viable technology for active light control, in situ electrical switching via resistive heaters integral to or embedded in the metasurface itself is highly desirable. In this context, good electrical conductors (metals) with high melting points (i.e., significantly above the melting point of commonly used phase-change alloys) are required. In addition, such metals should ideally have low plasmonic losses, so as to not degrade metasurface optical performance. This essentially limits the choice to a few noble metals, namely, gold and silver, but these tend to diffuse quite readily into phase-change materials (particularly the archetypal Ge2Sb2Te5 alloy used here), and into dielectric resonators such as Si or Ge. In this work, we introduce a novel hybrid dielectric/plasmonic metasurface architecture, where we incorporated a thin Ge2Sb2Te5 layer into the body of a cubic silicon nanoresonator lying on metallic planes that simultaneously acted as high-efficiency reflectors and resistive heaters. Through systematic studies based on changing the configuration of the bottom metal plane between high-melting-point diffusive and low-melting-point nondiffusive metals (Au and Al, respectively), we explicitly show how thermally activated diffusion can catastrophically and irreversibly degrade the optical performance of chalcogenide phase-change metasurface devices, and how such degradation can be successfully overcome at the design stage via the incorporation of ultrathin Si3N4 barrier layers between the gold plane and the hybrid Si/Ge2Sb2Te5 resonators. Our work clarifies the importance of diffusion of noble metals in thermally tunable metasurfaces and how to overcome it, thus helping phase-change-based metasurface technology move a step closer towards the realization of real-world applications.

scholarly journals Comparing optical performance of a wide range of perovskite/silicon tandem architectures under real-world conditions

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Manvika Singh ◽  
Rudi Santbergen ◽  
Indra Syifai ◽  
Arthur Weeber ◽  
Miro Zeman ◽  
...  
Keyword(s):  
Solar Cells ◽  
Real World ◽  
Solar Spectrum ◽  
Photocurrent Density ◽  
Angle Of Incidence ◽  
Optical Study ◽  
Optical Performance ◽  
Tandem Solar Cells ◽  
Bottom Cell ◽  
Wide Range

Abstract Since single junction c-Si solar cells are reaching their practical efficiency limit. Perovskite/c-Si tandem solar cells hold the promise of achieving greater than 30% efficiencies. In this regard, optical simulations can deliver guidelines for reducing the parasitic absorption losses and increasing the photocurrent density of the tandem solar cells. In this work, an optical study of 2, 3 and 4 terminal perovskite/c-Si tandem solar cells with c-Si solar bottom cells passivated by high thermal-budget poly-Si, poly-SiOx and poly-SiCx is performed to evaluate their optical performance with respect to the conventional tandem solar cells employing silicon heterojunction bottom cells. The parasitic absorption in these carrier selective passivating contacts has been quantified. It is shown that they enable greater than 20 mA/cm2 matched implied photocurrent density in un-encapsulated 2T tandem architecture along with being compatible with high temperature production processes. For studying the performance of such tandem devices in real-world irradiance conditions and for different locations of the world, the effect of solar spectrum and angle of incidence on their optical performance is studied. Passing from mono-facial to bi-facial tandem solar cells, the photocurrent density in the bottom cell can be increased, requiring again optical optimization. Here, we analyse the effect of albedo, perovskite thickness and band gap as well as geographical location on the optical performance of these bi-facial perovskite/c-Si tandem solar cells. Our optical study shows that bi-facial 2T tandems, that also convert light incident from the rear, require radically thicker perovskite layers to match the additional current from the c-Si bottom cell. For typical perovskite bandgap and albedo values, even doubling the perovskite thickness is not sufficient. In this respect, lower bandgap perovskites are very interesting for application not only in bi-facial 2T tandems but also in related 3T and 4T tandems.

P-75: Optical Performance of Compensated Normally Black and Normally White TN Modulated PLLCDs

2001 ◽  
Vol 32 (1) ◽  
pp. 842 ◽  
Author(s):  
S.-H. Ahn ◽  
A. B. Davey ◽  
W. A. Crossland
Keyword(s):  
Optical Performance ◽  
P 75
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