Dielectric-metal-dielectric Research Articles

Technological Advances to Maximize Solar Collector Energy Output: A Review

Since it is highly correlated with quality of life, the demand for energy continues to increase as the global population grows and modernizes. Although there has been significant impetus to move away from reliance on fossil fuels for decades (e.g., localized pollution and climate change), solar energy has only recently taken on a non-negligible role in the global production of energy. The photovoltaics (PV) industry has many of the same electronics packaging challenges as the semiconductor industry, because in both cases, high temperatures lead to lowering of the system performance. Also, there are several technologies, which can harvest solar energy solely as heat. Advances in these technologies (e.g., solar selective coatings, design optimizations, and improvement in materials) have also kept the solar thermal market growing in recent years (albeit not nearly as rapidly as PV). This paper presents a review on how heat is managed in solar thermal and PV systems, with a focus on the recent developments for technologies, which can harvest heat to meet global energy demands. It also briefs about possible ways to resolve the challenges or difficulties existing in solar collectors like solar selectivity, thermal stability, etc. As a key enabling technology for reducing radiation heat losses in these devices, the focus of this paper is to discuss the ongoing advances in solar selective coatings and working fluids, which could potentially be used in tandem to filter out or recover the heat that is wasted from PVs. Among the reviewed solar selective coatings, recent advances in selective coating categories like dielectric-metal-dielectric (DMD), multilayered, and cermet-based coatings are considered. In addition, the effects of characteristic changes in glazing, absorber geometry, and solar tracking systems on the performance of solar collectors are also reviewed. A discussion of how these fundamental technological advances could be incorporated with PVs is included as well.

Design and Simulation of a High-Selective Plasmon-Induced Reflectance in Coupled Dielectric-Metal-Dielectric Nano-structure for Senor Devices and Slow Light Propagation

A new framework of high-selective plasmonic-induced reflectance (PIR) in a plasmonic-induced transparency (PIT) system is presented by using planar dielectric-metal-dielectric (DMD) metamaterial nano-structure. We used glass as substrate, the first dielectric, gold as metal thin film, and prism as the second dielectric. The proposed plasmonic nano-structure has been investigated based on finite difference time domain (FDTD) method. Results show that by coupling incident light with dark and bright plasmonic modes, without losing the metamaterial structure symmetry, the transparent window is created at 1550 nm and can be tuned. The transmittance (T), reflectance (R), and absorbance (A) coefficients of the presented nano-structure can be considerably varied by changing the thickness of thin films and dimension of the strips. The reflectance coefficients of dip1 (200 THz) and dip2 (265.5 THz) are almost near zero, and the transmittance coefficient of PIR (227.1 THz) is 0.93. Also, the maximum sensitivity and figure of merit are 664 and 3.77 for reflectance dip2, respectively. Similarly, the maximum quality factor (Q) is 10.74 for reflectance dip1. The presented plasmonic metamaterial nano-structure with mentioned unique features is a good candidate for several applications such as multi-channel plasmonic filters, bio and refractive index sensors, optical antenna, and slow-light devices for using in optical nano-electronic circuits and systems.

Transparent electrode for top emission organiclight-emitting diode

Organic light-emitting diode (OLED) has been successfully used in mobile display (small area) and television display (large area). For small area display screens, the top emission structure is mostly adopted because of the limitation of display area. Top emission OLED (TEOLED) can get higher power efficiency at the same current density than traditional bottom emission devices because of its higher aperture-opening ratio. However, the most important part of top emission device is the preparation of transparent electrode. In summary, according to the method and material, TEOLED transparent electrode is divided into the following categories: (1) Transparent conductive oxide electrode (TCO); (2) ultrathin composite metal electrode; (3) dielectric/metal/dielectric (DMD) composite electrode; (4) nanomaterial electrodes, etc. The general oxide has great optical transmittance in the visible light range, but the thermal evaporation temperature is very high. It needs to be fabricated by sputtering, which damages the organic layer. The composite metal electrode can be made by thermal evaporation, which is simple and easy. It is adopted by most commercial products by now, however its transparency is relatively low. Nano materials have high transparency and can be fabricated for flexible electrodes, but because of the solution processing, it is easier to destroy the organic layer. DMD composite electrode not only has high transmittance, but also can use thermal evaporation method to form film, it is expected to become better choice of top electrode for TEOLED. In order to achieve the objective of producing top emitting OLED with excellent properties, it is most important to find enough transparent, high conductive, ohmic contact, film forming process without destroying organic layer and stable electrode material. Up to now, the researchers have proposed several methods for preparing barrier layer-ITO, pulsed laser deposition transparent conducting oxide, thermal evaporated ultrathin composite metal, DMD composite, nano-materials, etc. In this paper, the applications of these materials in the TEOLED transparent electrode are reviewed. By comparing the advantages and disadvantages of thin film electrode, the research progress of TEOLED transparent electrode is reviewed.

Multispectral surface plasmon resonance approach for ultra-thin silver layer characterization: Application to top-emitting OLED cathode

While dielectric/metal/dielectric (DMD) multilayer thin films have raised considerable interest as transparent and conductive electrodes in various optoelectronic devices, the knowledge of optical characteristics of thin metallic layers integrated in such structures is still rather approximate. The multispectral surface plasmon resonance characterization approach described in this work precisely aims at providing a rigorous methodology able to accurately determine the optical constants of ultra-thin metallic films. As a practical example, the refractive index and extinction dispersion curves of 8 to 25 nm-thick silver layers have been investigated. As a result, their extreme dependence on the layer thickness is highlighted, in particular in a thickness range close to the critical threshold value (∼10 nm) where the silver film becomes continuous and its electrical conductance/optical transmittance ratio particularly interesting. To check the validity of the revisited Ag layers constant dispersion curves deduced from this study, they were introduced into a commercial optical model software to simulate the behavior of various optoelectronic building blocks from the simplest ones (DMD electrodes) to much more complex structures [full organic light emitting device (OLED) stacks]. As a result, a much better prediction of the emission spectrum profile as well as the angular emission pattern of top-emitting OLEDs is obtained. On this basis, it is also shown how a redesign of the top encapsulation thin film of OLEDs is necessary to better take benefit from the advanced DMD electrode. These results should particularly interest the micro-OLED display field where bright and directive single color pixel emission is required.

Dielectric-Metal-Dielectric (D-M-D) infrared (IR) heat reflectors

Sunlight is the primary source of light in the buildings and automobiles. However, infrared (IR) radiations in the sunlight result in heat generation. In this work, dielectric-metal-dielectric (D-M-D) heat reflectors are demonstrated which is transparent for visible light 400-700 nm while reflecting IR radiations above 700 nm. These reflectors are based on a TiO2-Ag-TiO2 sandwich structure with 22 nm of the thickness of each layer shows the maximum transmission of 83 % theoretically and 81 % experimentally in the visible wavelengths region observed by ellipsometer; a maximum reflection of IR wavelengths was also observed. The study was also extended to experimental verification of heat transmission by testing these reflectors both under IR lamp and sun in the month of June 2016. Experimental results confirm less heat transfer through these filters as compared to the commercially available tinting paper. As a practical application, these reflectors can be used in automobiles and houses during summer to reflect back the excessive heat from the sun.

MoOx/Ag/MoOx transparent electrode by solution process

We have investigated a dielectric–metal–dielectric (DMD) multilayer film, which is unique as compared with such conventional transparent conductive oxides as indium tin oxide (ITO). In this study, we have selected MoO3 and Ag as the dielectric material and metal, respectively, and employed a nano-mist method in addition to a vacuum evaporation one. The transmission spectra of the films indicated that the Ag morphology changed from isolated islands to continuous layers with increasing Ag layer thickness, and that the morphology change was enhanced by MoO3. Then, MoO3/Ag/MoO3 (MAM) multilayer-structured transparent electrodes could be fabricated by a nano-mist method as well as by a vacuum evaporation one. Comparative examination is made on the properties of MAM films fabricated by these two methods for their application.

D-M-D Plasmonic Anti-Reflector for Next-Generation Thin c-Si Solar Cell Applications

In this paper, focus is on the light trapping surface in crystalline silicon (c-Si) solar cells where thinner c-Si wafers are expected to be used by industry to reduce the cost of cell manufacturing. Currently, 180-μm-thick wafers are being used for fabricating c-Si solar cells where textured surface coated with silicon nitride (SiN x ) anti-reflector enhances the light trapping. However, surface texturing process roughens the surface and increases the probability of more surface recombination as the wafer thickness decreases. This paper presents an analytical analysis for the development of plasmonic anti-reflector as an alternative to traditional texturization for next-generation thin c-Si solar cells. The analysis indicates that loss in current generation due to Si wafer thickness reduction up to 100 μm from currently used 180 μm would not be more than 0.5 mA/cm2 if the light trapping structure is excellent. A 100-μm wafer thickness reduction would increase the front escape of light but not more than 1%. PC1D simulation incorporating experimental reflectance from an equivalent 100-μm thin c-Si wafer-based solar cell structure having proposed dielectric-metal-dielectric (D-M-D)-based anti-reflector indicates 1.2–1.3 mA/cm2 current enhancement when compared with a standard SiN x anti-reflector.

Recent progress of multilayer composite transparent conductive film

Transparent conductive films (TCFs), which transmit light and conduct electrical current simultaneously, are widely used as transparent electrodes across technical fields such as flat-panel displays, touch screens, solar cells and light-emitting devices. In present, TCO films such as tin-doped indium oxide (ITO), aluminum-doped zinc oxide (AZO) and fluorine doped SnO2 (FTO) are the most widely used transparent electrodes in these devices. However, the manufacturing of ITO film requires precious raw materials indium and other TCO films still have to improve their conductivity and transmittance in visible region. Moreover, due to the inherent brittleness of oxide materials, the flexibilities of TCO films are poor, which could not meet the application requirements of flexible electronics. More and more researchers are focusing on finding new transparent conductive materials as substitutes. Multilayer composite TCFs based on ultrathin metal film exhibit high conductivity, good transparency and excellent flexibility. In this feature article, we review the recent progress of multilayer composite TCFs with dielectric/metal/dielectric (DMD) structure by describing the basic principles, the materials and thickness selection of each layer, the structural types, the methods of photoelectric performance improvement, and other important properties of multilayer composite TCFs with the DMD structure. Due to the good conductivity and ductility of metal layers, multilayer composite TCFs with the DMD structure show low sheet resistance and excellent mechanical flexibility. Some metals such as Ag, Au, Cu, Al, Pd, Pt, Mo, Ni, In and metal alloys have been used as the metal interlayer of DMD electrodes. Among them, the most frequently used metals are Ag, Cu and Au. The two dielectric layers in DMD electrodes may be utilized to improve the overall transmittance in the visible spectral range by optical interference within the multilayer structure, while their thickness can be chosen as a function of the device properties requested. As the metal provides a high lateral conductivity, the dielectric layers in the DMD electrodes do not require being highly conductive, therefore they can be selected in a wide range of materials such as ITO, AZO, FTO, MoO3, WO3, TiO2, ZnS, etc. Experimental data have shown that the same transmittance and sheet resistance values could be obtained with DMD structures composed of different dielectric and metal combinations. In addition, high temperature deposition and annealing are not required to achieve good electrical conductivity, in spite of the higher resistivity achieved by dielectric films prepared without heating. Therefore, DMD electrodes are suitable to deposit onto unheated plastic substrates by continuous roll-to-roll techniques. The efficiencies of DMD electrodes are seriously constrained by a deleterious trade-off between the optical transmittances and electrical conductivities of the metal layers. An improvement in the electrical conductivity requires an increase in the thickness of the metal layer, but the increase of thickness seriously reduces the transmittance. Moreover, due to the three dimensional island growth mode of metal layers deposited using vacuum coating techniques, the metal film usually has a threshold thickness that is the minimum possible thickness for forming a continuous layer to provide sufficient electrical paths. Below the threshold thickness, both the electrical resistivity and the optical absorption rapidly increase. The conductivity and transmittance of a thin metal layer are normally optimized at or near the percolation threshold thickness, since a high optical transmission is required in most cases. Therefore, reducing the percolation threshold thickness of metal layers is a key to improve their conductivity and transmittance simultaneously. In the latest years, some impressive improvements have been achieved by controlling the underlay material, seed layer, dopants and deposition rate at the deposition of metal layer. So far, multilayer composite TCFs with the DMD structure have primarily been applied in solar cell and light-emitting devices, where multilayer composite TCFs may be used as cathodes or anodes, even intermediate electrodes due to the electrode work function easily adjusted by the selection of dielectric layer material. When the multilayer electrodes are applied in solar cell, higher power conversion efficiencies have been achieved compared with devices fabricated on single-layer TCO electrodes. Although there are some challenges yet to overcome to optimize the processing and performance of multilayer composite TCFs, multilayer composite TCFs with the DMD structure remain a highly suitable candidate for various flexible electronic applications in the near future.

Bifunctional MoO3-WO3/Ag/MoO3-WO3 Films for Efficient ITO-Free Electrochromic Devices.

Dielectric-metal-dielectric (DMD) trilayer films, served as both electrochromic (EC) film and transparent conductor (TC), have exhibited great potential application in low-cost, ITO-free electrochromic devices (ECDs). However, recent reports on the DMD-based ECDs revealed that the response time and the optical modulation properties were not very satisfactory. Here, the mixed MoO3-WO3 materials were first introduced as the dielectric layer to construct an EC-TC bifunctional MoO3-WO3/Ag/MoO3-WO3 (MWAMW) film, which demonstrates strong and broad-band optical modulation in the visible light region, fast color-switching time (2.7 s for coloration and 4.1 s for bleaching), along with high coloration efficiency (70 cm2 C-1). The electrical structure and electrochemical reaction kinetics analysis revealed that the improved EC performances are associated with the increased electron intervalence transition together with the fast charge-transfer and ion-diffusion dynamics.

Thermal durability of AZO/Ag(Al)/AZO transparent conductive films

Effects of Al doping on surface morphology, sheet resistance, optical transmission spectra, and thermal durability of a thin Ag layer and AZO/Ag/AZO dielectric/metal/dielectric (DMD) transparent conductive films (TCFs) were investigated. The 1.7 at. % Al doping suppressed the initial island growth of a thin Ag layer and the plasmon resonant absorption dip in the optical transmission spectra. The threshold thickness of percolation conductivity was reduced from 9–10 (pure Al layer) to 5–6 nm (1.7 at. % Al-doped Ag layer). Al doping in the Ag layer improved the thermal durability of AZO/Ag/AZO-DMD TCFs. The threshold temperature for Ag void formation increased from 400 °C (DMD with pure Ag layer) to 600 °C (DMD with a 10.5 at. % Al-doped Ag layer). The optimum annealing temperature increased from 300 °C (DMD with a pure Ag layer) to 500 °C (DMD with a 10.5 at. % Al-doped Ag layer). Maximum figures of merit (FOM) were 0.5 × 10−2 and 1.1 × 10−2 Ω−1 for the DMD with a pure Ag layer and that with a 10.5 at. % Al-doped Ag layer, respectively.

Effect of Al doping in the Ag layer of MgZnO/Ag/MgZnO dielectric/metal/dielectric UV–visible transparent conductive films

AbstractTransparent conductive films (TCFs) with dielectric/metal/dielectric (DMD) structure covering the UVA (λ = 315–380 nm) and visible wavelength region (380–780 nm) were fabricated using Al‐doped Mg0.4Zn0.6O (AMZO) dielectric and 1.7 at% Al‐doped Ag (Ag(Al)) metal layers. The AMZO/Ag(Al)/AMZO‐DMD film with a 7 nm thick Ag(Al) layer after annealing in vacuum at 400 °C showed superior performance as a TCF, i.e., average transmittance from UVA to visible region (315–780 nm) of 88.2% and sheet resistance of 7.6 Ω/sq. The effect of Al doping on optical transmission, sheet resistance, surface morphology, and thermal durability of the AMZO/Ag(Al)/AMZO‐DMD films were also investigated. The 1.7 at% Al doping suppressed the initial island growth of the thin Ag layer and the plasmon resonance absorption dipped in the optical transmission spectra. Al doping in the Ag layer also improved the thermal durability of AMZO/Ag/AMZO‐DMD films. The threshold temperature for Ag void formation caused by metal segregation increased from 300 °C (DMD with a pure Ag layer) to 400 °C (DMD with an Al‐doped Ag layer). (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Ar plasma irradiation improved optical and electrical properties of TiO₂/Ag/TiO₂ multilayer thin film.

Embedding a thin metal layer between two thin dielectric or semiconductor layers [dielectric/metal/dielectric (DMD)] leads to a kind of transparent electrode that is promising as a substitute for the currently widely applied indium tin oxide electrode. However, the optical and electrical properties of DMD still wait for further improvement. In this study, Ar plasma irradiation (API) was, for the first time to our knowledge, applied to improve the optical and electrical properties of a TiO2/Ag/TiO2 electrode that was fabricated by electron-beam evaporation of TiO2 and electric-resistance heating of high purity Ag under vacuum. Ar plasma was produced by radio frequency glow discharge. The Ag layer was bombarded before the second layer of TiO2 was deposited. The electrode with configuration of TiO2 (24 nm)/Ag(14 nm)/TiO2 (24 nm) after API for 10 s shows excellent performance. The mean transmittance between 370 and 800 nm reaches 94% and the sheet resistance is as low as 6 Ω/sq, while Haacke's figure of merit is as high as 112×10(-3) Ω(-1). The improvement mechanism is discussed based on field emission scanning electron microscope images and absorption spectra. The improvement is attributed to the fact that API reduces the localized surface plasmon resonance of Ag nanoparticles and makes the Ag film thinner and denser.

Opto-Electrical Performance Improvement of Mono c-Si Solar Cells Using Dielectric–Metal–Dielectric (D-M-D) Sandwiched Structure-Based Plasmonic Anti-Reflector

Mono c-Si solar cells based on plasmonic anti-reflector, an ultra-thin silver (Ag) film sandwiched between silicon nitride (SiNx) layers on non-textured c-Si surface, have been explored. Prior to solar cell fabrication, the plasmonic anti-reflector structure was optimized separately by varying different thicknesses of top and bottom SiNx layers and the sandwiched ultra-thin Ag film. For broad wavelength range (300–1200 nm), minimum weighted reflectance was observed in the range of 8–9 %, for the top and bottom SiNx layers having 70–80-nm thickness. The refractive index of top and bottom SiNx layers was in the range of 1.77–1.80 and 1.92–1.96, respectively. A 180-μm non-textured mono c-Si solar cell is fabricated with plasmonic anti-reflector, having top and bottom SiNx layer thickness of 80-nm and 8–9-nm sandwiched ultra-thin Ag layer, resulted in 17 % solar cell efficiency. The measured efficiency was 1.8 % higher compared to 180-μm mono c-Si solar cell with standard 80 nm SiNx anti-reflector. The short circuit current density (J sc) extracted from external quantum efficiency (EQE) has shown 0.5 mA/cm2 enhancement for the dielectric–metal–dielectric (D-M-D) sandwiched structure (plasmonic anti-reflector)-based solar cell compared to standard SiNx anti-reflection coating (ARC) structure-based solar cell. EQE enhancement was seen for all wavelengths above 700 nm with maximum 25–26 % enhancement at around 1125 nm. Also, in UV wavelength region (300–400 nm), EQE enhancement was seen with maximum 25 % enhancement at around 370 nm. Possible phenomenon for improved anti-reflection and EQE in D-M-D-based plasmonic anti-reflector has been discussed.

Photon harvesting, coloring and polarizing in photovoltaic cell integrated color filters: efficient energy routing strategies for power-saving displays

We describe the integral electro-optical strategies that combine the functionalities of photovoltaic (PV) electricity generation and color filtering as well as polarizing to realize more efficient energy routing in display technology. Unlike the conventional pigment-based filters and polarizers, which absorb substantial amounts of unwanted spectral components and dissipate them in the form of heat, we propose converting the energy of those photons into electricity by constructing PV cell-integrated color filters based on a selectively transmitting aluminum (Al) rear electrode perforated with nanoholes (NHs). Combining with a dielectric-metal-dielectric (DMD) front electrode, the devices were optimized to enable efficient cavity-enhanced photon recycling in the PV functional layers. We perform a comprehensive theoretical and numerical analysis to explore the extraordinary optical transmission (EOT) through the Al NHs and identify basic design rules for achieving structural coloring or polarizing in our PV color filters. We show that the addition of thin photoactive polymer layers on the symmetrically configured Al NH electrode narrows the bandwidth of the EOT-assisted high-pass light filtering due to the strongly damped anti-symmetric coupling of the surface modes excited on the front and rear surface of the Al NHs, which facilitates the whole visible coloring with relatively high purity for the devices. By engineering the cut-off characteristics of the plasmonic waveguide mode supported by the circular or ellipsoidal Al NHs, beyond the photon recycling capacity, PV color filters and PV polarizing color filters that allow polarization-insensitive and strong polarization-anisotropic color filtering were demonstrated. The findings presented here may shed some light on expanding the utilization of PV electricity generation across new-generation energy-saving electrical display devices.

MoO3/Ag/MoO3 anode for organic light-emitting diodes and its carrier injection property

We report on the application of the dielectric/metal/dielectric (DMD) structure consisting of a molybdenum trioxide (MoO3)/silver (Ag)/MoO3 stack as the transparent electrode in organic light-emitting diodes (OLEDs). Bright emission similar to that of the indium–tin-oxide anode (ITO) device was obtained from the OLEDs with the DMD anode. Also, the barrier height at the interface of DMD/bis[N-(1-naphthyl)-N-phenyl] benzidine (α-NPD) is similar to that at the ITO/α-NPD interface. The DMD electrode is a promising anode for OLEDs.

Top illuminated organic photodetectors with dielectric/metal/dielectric transparent anode

The top illuminated organic photodetectors (OPDs) with a Dielectric/Metal/Dielectric (DMD) transparent anode are fabricated. The transparent electrode is composed of molybdenum trioxide (MoO3)/silver (Ag)/MoO3 layers and zinc oxide (ZnO)/aluminum (Al) is used for bottom cathode. The optimized DMD electrode has an optical transmittance of 85.7% at the wavelength of 546nm and sheet resistance of ∼6Ω/sq. The fabricated OPDs exhibit a high detectivity and wide range linearity.

High-performance NiO/Ag/NiO transparent electrodes for flexible organic photovoltaic cells.

Transparent electrodes with a dielectric-metal-dielectric (DMD) structure can be implemented in a simple manufacturing process and have good optical and electrical properties. In this study, nickel oxide (NiO) is introduced into the DMD structure as a more appropriate dielectric material that has a high conduction band for electron blocking and a low valence band for efficient hole transport. The indium-free NiO/Ag/NiO (NAN) transparent electrode exhibits an adjustable high transmittance of ∼82% combined with a low sheet resistance of ∼7.6 Ω·s·q(-1) and a work function of 5.3 eV after UVO treatment. The NAN electrode shows excellent surface morphology and good thermal, humidity, and environmental stabilities. Only a small change in sheet resistance can be found after NAN electrode is preserved in air for 1 year. The power conversion efficiencies of organic photovoltaic cells with NAN electrodes deposited on glass and polyethylene terephthalate (PET) substrates are 6.07 and 5.55%, respectively, which are competitive with those of indium tin oxide (ITO)-based devices. Good photoelectric properties, the low-cost material, and the room-temperature deposition process imply that NAN electrode is a striking candidate for low-cost and flexible transparent electrode for efficient flexible optoelectronic devices.

Investigation on optical and electrical properties of ZnO sandwich structure with metal interlayer

The dielectric–metal–dielectric (DMD) sandwich structure is fabricated by the RF magnetron sputtering. The effects of sputtering voltage, thickness of the metal layer, and process temperatures on the optical, crystalline structure, and electrical properties of the zinc oxide (ZnO) films were investigated by UV–vis spectrometry, X-ray diffraction and electron energy loss spectroscopy (EELS). Silver, copper and aluminum are used for the DMD sandwich metal layer in this research. The thickness of the dielectric films is decided by admittance loci analysis base on the selected metal characteristic. The optical average transmittance in the visible spectrum and bulk resistivity of the DMD with intermediate Ag layer can reach 85% and 3 × 10−5 Ω cm, respectively.

Optical Effect of Surface Morphology of Ag on Multilayer Electrode Applications for OLEDs

We investigated the optical properties of a dielectric-metal-dielectric (DMD) electrode in relation to the surface morphology of Ag. We intentionally modified the number of voids and the surface coverage of the Ag layer. Normal and oblique incident configurations for transmittance measurement were employed to establish the relations between the Ag morphology and optical transmittance of the DMD electrode. For the configuration of MoO3/Ag/MoO3 (MAM), variation in the surface morphology of the Ag minimized the light scattering loss and the absorption of photons. This could lead to 18.6% enhancement of the transmittance at λ = 550 nm. The optical out-coupling was also enhanced in OLEDs, which was based on the MAM anode incorporating the continuous Ag film.

Extraction of optimized parameters for Si0.6Ge0.4 material and SPP mode propagation through Si0.6Ge0.4/Ag/Si0.6Ge0.4 waveguide

The Lorentz model and modified Debye model (MDM) parameters for Si0.6Ge0.4 are presented. A nonlinear optimization algorithm is developed. The obtained parameters are used to determine the complex relative permittivity of Si0.6Ge0.4, and compared with the experimental data for validation. Finally the obtained parameters are used to analyze the properties of symmetric surface plasmon polariton (SPP) mode propagation in a dielectric-metal-dielectric (DMD) material constructed with silver (Ag) and Si0.6Ge0.4 for further verifying the extracted parameters.