Enhancing the photoluminescence response from thick Ge-on-Si layers using the photonic crystals

2021 ◽  
Author(s):  
Dmitry V Yurasov ◽  
Artem N Yablonskiy ◽  
Natalya A Baidakova ◽  
Mikhail V Shaleev ◽  
Ekaterina E Rodyakina ◽  
...  
Keyword(s):  
Photonic Crystals ◽  
Room Temperature ◽  
Optically Active ◽  
Far Field ◽  
Two Dimensional ◽  
Wave Analysis ◽  
Room Temperature Photoluminescence ◽  
Order Of Magnitude ◽  
Spectroscopy Optical ◽  
Photoluminescence Response

Abstract More than an order of magnitude enhancement of the room-temperature photoluminescence (PL) signal from rather thick Ge layers grown on Si(001) was obtained by utilization of the two-dimensional photonic crystals (PhC). A set of PhCs with different periods and filling factors was fabricated and studied using a micro-PL spectroscopy. Optical features of the fabricated PhCs were also theoretically modeled using a rigorously coupled wave analysis which allowed to bring the observed peaks in the PL response into correlation with the different modes of PhC. In particular, we were able to associate the well-resolved peaks in the PL spectra with the optically active modes of the PhCs. The obtained results proved the possibility of using a homogeneously distributed active medium in PhCs without the formation of specially designed cavities in order to redistribute the internal emitted light into the required modes and efficiently extract it to the far field. The relative simplicity and higher tolerance to fabrication imperfections, as well as the large working area of such kind of PhCs as compared to PhCs with microcavities can be advantageous for creating a PhC-based Si-compatible light source for the telecom band.

scholarly journals Far-Field Focus and Dispersionless Anticrossing Bands in Two-Dimensional Photonic Crystals

2007 ◽  
Vol 2007 ◽  
pp. 1-8
Author(s):  
Xiaoshuang Chen ◽  
Renlong Zhou ◽  
Yong Zeng ◽  
Hongbo Chen ◽  
Wei Lu
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystals ◽  
Negative Refraction ◽  
Far Field ◽  
Two Dimensional ◽  
Surface Polaritons ◽  
Concave Lens ◽  
Bloch Mode ◽  
Two Dimensional Photonic Crystal ◽  
Photonic Band

We review the simulation work for the far-field focus and dispersionless anticrossing bands in two-dimensional (2D) photonic crystals. In a two-dimensional photonic-crystal-based concave lens, the far-field focus of a plane wave is given by the distance between the focusing point and the lens. Strong and good-quality far-field focusing of a transmitted wave, explicitly following the well-known wave-beam negative refraction law, can be achieved. The spatial frequency information of the Bloch mode in multiple Brillouin zones (BZs) is investigated in order to indicate the wave propagation in two different regions. When considering the photonic transmission in a 2D photonic crystal composed of a negative phase-velocity medium (NPVM), it is shown that the dispersionless anticrossing bands are generated by the couplings among the localized surface polaritons of the NPVM rods. The photonic band structures of the NPVM photonic crystals are characterized by a topographical continuous dispersion relationship accompanied by many anticrossing bands.

scholarly journals NEGATIVE REFRACTION AND SUBWAVELENGTH FOCUSING USING PHOTONIC CRYSTALS

2004 ◽  
Vol 18 (25) ◽  
pp. 1275-1291 ◽  
Author(s):  
EKMEL OZBAY ◽  
KAAN GUVEN ◽  
ERTUGRUL CUBUKCU ◽  
KORAY AYDIN ◽  
B. KAMIL ALICI
Keyword(s):  
Optical Properties ◽  
Photonic Crystals ◽  
Negative Refraction ◽  
Numerical Study ◽  
Effective Index ◽  
Index Of Refraction ◽  
Far Field ◽  
Two Dimensional ◽  
Flat Lens ◽  
Effective Index Of Refraction

In this article, we present an experimental and numerical study of novel optical properties of two-dimensional dielectric photonic crystals (PCs) which exhibit negative refraction. We investigate two mechanisms which utilize the band structure of the PC to generate a negative effective index of refraction (n eff <0) and demonstrate the negative refraction experimentally. To the isotropic extend of n eff , different PC slab structures are employed to focus the radiation of a point source. It is shown experimentally that the PC can generate an image of the source with subwavelength resolution in the vicinity of the PC interface. Using a different PC, one can also obtain a far field focusing. In the latter case, we explicitly show the flat lens behavior of the structure. These examples indicate that PC-based lenses can surpass limitations of conventional lenses and lead to novel optics applications.

Fabrication of ZnO Nanowall-Based Hydrogen Gas Nanosensor

2013 ◽  
Vol 684 ◽  
pp. 21-25 ◽  
Author(s):  
Tse Pu Chen ◽  
Sheng Po Chang ◽  
Shoou Jinn Chang
Keyword(s):  
Seed Layer ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Hydrogen Gas ◽  
Two Dimensional ◽  
Defect Related Emission ◽  
Room Temperature Photoluminescence ◽  
Hydrogen Sensing ◽  
Uv Emission ◽  
Sensing Characteristics

Two-dimensional ZnO nanowalls were rapidly grown on glass substrate by thermal evaporation at low temperature without any catalysts or the pre-deposition of a ZnO seed layer on the substrate. Most of the ZnO nanowalls grown at 450°C were vertical on substrate and they were about 70-200 nm thick and 2 µm long. The room-temperature photoluminescence (PL) spectra showed a strong intrinsic ultraviolet (UV) emission and a weak defect-related emission. Hydrogen-sensing characteristics of the ZnO nanowalls have been investigated, and that make them become attractive candidates for gas sensor.

scholarly journals Far-field of GaN film-transferred green light-emitting diodes with two-dimensional photonic crystals

2009 ◽  
Vol 17 (11) ◽  
pp. 8795 ◽  
Author(s):  
Chun-Feng Lai ◽  
Jim-Yong Chi ◽  
Hao-Chung Kuo ◽  
Hsi-Hsuan Yen ◽  
Chia-En Lee ◽  
...  
Keyword(s):  
Photonic Crystals ◽  
Light Emitting Diodes ◽  
Green Light ◽  
Far Field ◽  
Two Dimensional ◽  
Light Emitting ◽  
Gan Film

scholarly journals Two-dimensional hybrid perovskites sustaining strong polariton interactions at room temperature

2019 ◽  
Vol 5 (5) ◽  
pp. eaav9967 ◽  
Author(s):  
A. Fieramosca ◽  
L. Polimeno ◽  
V. Ardizzone ◽  
L. De Marco ◽  
M. Pugliese ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Degrees Of Freedom ◽  
Room Temperature ◽  
Optical Cavity ◽  
Oscillator Strengths ◽  
Layered Perovskite ◽  
Two Dimensional ◽  
Coherent Coupling ◽  
Highly Nonlinear ◽  
Order Of Magnitude

Polaritonic devices exploit the coherent coupling between excitonic and photonic degrees of freedom to perform highly nonlinear operations with low input powers. Most of the current results exploit excitons in epitaxially grown quantum wells and require low-temperature operation, while viable alternatives have yet to be found at room temperature. We show that large single-crystal flakes of two-dimensional layered perovskite are able to sustain strong polariton nonlinearities at room temperature without the need to be embedded in an optical cavity formed by highly reflecting mirrors. In particular, exciton-exciton interaction energies are shown to be spin dependent, remarkably similar to the ones known for inorganic quantum wells at cryogenic temperatures, and more than one order of magnitude larger than alternative room temperature polariton devices reported so far. Because of their easy fabrication, large dipolar oscillator strengths, and strong nonlinearities, these materials pave the way for realization of polariton devices at room temperature.

scholarly journals Far-field detection of two-dimensional terahertz topological photonic crystals

2021 ◽  
Vol 51 (5) ◽  
pp. 054207
Author(s):  
Yi LIU ◽  
ShaoXian LI ◽  
WeiLi ZHANG ◽  
XieYu CHEN ◽  
JiaJun MA ◽  
...  
Keyword(s):  
Photonic Crystals ◽  
Far Field ◽  
Two Dimensional ◽  
Field Detection

scholarly journals Люминесценция пространственно упорядоченных одиночных и групп самоформирующихся Ge(Si) наноостровков, встроенных в фотонные кристаллы

2020 ◽  
Vol 54 (8) ◽  
pp. 708
Author(s):  
Ж.В. Смагина ◽  
А.В. Новиков ◽  
М.В. Степихова ◽  
В.А. Зиновьев ◽  
Е.Е. Родякина ◽  
...  
Keyword(s):  
Photonic Crystals ◽  
Room Temperature ◽  
Two Dimensional ◽  
Pronounced Increase ◽  
Ordered Array ◽  
Pl Intensity ◽  
Self Assembled

Photoluminescence (PL) properties of arrays of spatially ordered single Ge(Si) self-assembled islands, including embedded in two-dimensional photonic crystals (PhC), was studied. Incorporation of an array of ordered single islands and their groups into PhC significantly increases the intensity of their PL signal. The most pronounced increase in intensity (up to 30 times at nitrogen temperatures) is observed for an ordered array of single islands. The increase in PL intensity is associated with interaction of island emission with the radiation modes of the PhC, which is more efficient for an array of spatially ordered single islands. As result PL from single ordered Ge(Si) islands embedded in PhC was observed up to room temperature.

scholarly journals Упорядоченные массивы квантовых точек Ge(Si), встроенные в двумерные фотонные кристаллы

2019 ◽  
Vol 53 (10) ◽  
pp. 1366
Author(s):  
Ж.В. Смагина ◽  
В.А. Зиновьев ◽  
Е.Е. Родякина ◽  
Б.И. Фомин ◽  
М.В. Степихова ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Photonic Crystals ◽  
Spectral Range ◽  
Silicon Surface ◽  
Room Temperature ◽  
Two Dimensional ◽  
Growth Modes ◽  
Self Assembled

Two approaches to the integration of ordered Ge(Si) self-assembled quantum dots (QDs) into two-dimensional photonic crystals (PhC) are considered in the paper. The first approach involves the synthesis on the structured silicon surface of the ordered Ge(Si) QD array, on which PhC is then formed. In the second approach, the PhC itself serves as the template for the ordered QD growth. It is shown that varying the diameter of PhC holes in the framework of the second approach, two growth modes of QDs can be realized, when they are formed inside or outside the PhC holes. For structures with ordered QDs built into PhC, an increase in the intensity of the photoluminescence signal was detected at room temperature in the spectral range of 0.9-1.2 eV, which is associated with the interaction of the emission with the radiation modes of PhC.

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