Double-layer Antireflection Coatings Research Articles

Analysis of CeO2/SiO2 double-layer thin film stack with antireflection effect for silicon solar cells

This study introduces CeO2/SiO2 double-layer film stacks and its antireflection coating effect. Optical properties were analyzed by spectrophotometer measurements; surface morphology and cross-sections were observed by Scanning Electron Microscopy (SEM); elemental distributions and crystallographic properties were determined by Energy Dispersive Spectroscopy (EDS) and X-ray Diffraction (XRD) measurements. Average reflectance of single-layer 0.3MSiO2, 0.6MSiO2, and 0.3MCeO2 thin films were 30.54%, 20.12%, and 14.23%, respectively. Average reflectance was decreased significantly down to 5.9% by 0.3MCeO2/0.6MSiO2 double-layer thin films comparing to those of the results of single-layer films and bare silicon surface reflection (~40%). Antireflective effect of the films on solar cells was estimated by simulation using the measured reflection data. Simulated solar cells indicate that 0.3MCeO2/0.6MSiO2 double-layer antireflective coatings are capable to increase the efficiency significantly and conversion efficiency of 21.7% could be achieved.

Optimization design of surface optical characteristics of space solar cells based on transfer matrix method

The antireflection coating (ARC) can improve the photoelectric conversion efficiency of photovoltaic (PV) cells. In this paper, the influence of film thickness and refractive index of single-layer and double-layer ARC on solar light absorption under different spectral conditions is simulated by the transfer matrix method. The optimum values of ARC film thickness and refractive index are obtained. To optimize it at AM 0 (air mass 0) solar irradiance, a 66 nm thick SiN x ARC with a refractive index of 2.0 was used. The PV cell’s maximum power density is 89.87. The maximum power density of the PV cell with double-layer SiN x as ARC is 90.94. This work provides a theoretical basis for the application of ARC in ground PV power generation systems and space solar power systems.

Modelling and analysis of high efficiency silicon solar cell using double layers anti-reflection coatings (ARC)

The modernization that is currently taking over across the world is resulting in numerous advancements in a variety of industries, and the most notable and apparent development is the rising use of solar energy, which has become more prevalent every day. Most companies, residences, schools, and other organizations rely mostly on solar energy as the main source of electricity. It was discovered that anti-reflective coating (ARC) had been applied to solar cells with the goal of increasing power conversion efficiency, decreasing reflection loss, and improving absorption. Although a single layer of ARC is sufficient, applying an additional layer might improve the solar cell application’s effectiveness. Hence, the modeling and analysis of double layers of anti-reflection coating (ARC) with different types of materials have been investigated and evaluated using personal computer one-dimensional (PC1D) simulation software. In this study, the double-layer anti-reflection coating on the solar cell was modeled using PC1D, where this software allowed for one-dimensional simulation of the parameters required for the operation of semiconductor-based solar energy systems. The PC1D simulation reveals that SiO2/TiO2 has the highest efficiency (22.82%) and lowest reflection compared to Si3N4/TiO2 and ZnO/TiO2. Also, SiO2/TiO2 generates the highest external quantum efficiency (EQE) among ARC double layers, making it ideal for silicon solar cell applications in order to boost the solar cell’s efficiency. The results for the effects of current, voltage, reflection, and EQE of the different double layers of ARC have also been studied in this paper.

High wear resistant double-layer antireflection coatings for near-infrared vehicular lidar

High wear resistant double-layer antireflection coatings for near-infrared vehicular lidar

Designing multifunctional silica coatings for enhanced broadband antireflection and microfiber contamination sensing

Multifunctional silica coatings find diverse applications in solar energy conversion and pollution monitoring sensors due to their suitability for mass manufacturing. However, the challenge lies in producing robust silica coatings on a large scale with tunable refractive index. This work presents a two-step acid/base catalyzed sol–gel process for synthesizing multifunctional silica coatings with adjustable refractive index. The coatings' porous microstructure allows them to be used as double-layer broadband antireflective coatings and enhances the sensitivity of contamination sensors. The optimized double-layer coatings, designed using computer-aided techniques, demonstrate excellent broadband antireflective performance in the visible regions and high environmental durability. They achieve a maximum transmittance of 99.87% at 591 nm, with an average transmittance of 99.40% in the visible region (400–800 nm) and 98.63% from 400 nm to 1100 nm. Additionally, the coatings exhibit robust abrasion resistance and enhanced surface hydrophobicity with a water contact angle increased from 30° to 126° through HMDS treatment. This work investigated the particle growth mechanism and the relationship between silica nanoparticle microstructure and antireflective coating properties. Furthermore, the coatings' presence of abundant micropores allows successful application onto microfiber contamination sensors, the additional loss increases from 26.40 dB to 37.69 dB over 140 min and decreases to 31.55 dB within one minute, demonstrating rapid adsorption and desorption rates. The work successfully achieves a wide range of adjustable refractive index while maintaining excellent mechanical and optical properties, addressing the traditional trade-off between high porosity and poor mechanical stability. These rationally designed multifunctional silica coatings hold great potential for high-quality broadband antireflection and high sensitivity in microfiber contamination sensing.

Comparative Study of Polarization‐Dependent Conversion Efficiency of GaAs and Si Solar Cells at Oblique Incident Angles Using Surface DLAR Coating of MgF2/ZnSe

AbstractThe aim of this work is to minimize reflection losses in order to increase the efficiency of solar cells by using anti‐reflection coatings (ARCs). Despite extensive research on improving solar cell conversion efficiency at normal incidence, development at angle of incidence has received little attention. Thus, the reflectivity of single‐layer ARC (SLARC) MgF2 and ZnSe, double‐layer ARC (DLARC), MgF2/ZnSe on Si, and GaAs substrates at transverse electric (TE) and transverse magnetic (TM) modes of polarization in the visible and near‐IR regions for different angles of incidence is analyzed. The optical and electrical properties of Si and GaAs solar cells are analyzed by using the reflectance spectra of SLARC and DLARC at various angles of incidence for the TM and TE modes of polarization under the solar power spectrum (AM1.5). The achieved results due to the effect of DLARC are compared for Si and GaAs solar cells. From these analyses, it is concluded that MgF2/ZnSe is an appropriate DLARC for the range of wavelengths 400–800 nm at 10°–30° angles of incidence in TM mode for tuning the optical and electrical properties of Si and GaAs substrates for terrestrial applications.

Ray Tracer Simulation of Si-Based Solar Cells using Al2O3/ITO as Double Layers Anti Reflective Coating

The solar cell has become one of the options for a greener world. Various studies have been done to achieve a solar cell with high efficiency and reasonable price. This study’s objective is to investigate how the thickness and base angle of the front layer affect the optical and electrical characteristics of Si-Based Solar cells. To accomplish this study, heterojunction solar cells using Al2O3/ITO as the double layer anti-reflection coating are analyzed using the Wafer Ray Tracer simulation by the PV Lighthouse. Al2O3 and ITO layers are used as a double anti-reflection coating (DLARC) in the light trapping strategy to support the reflection, absorption, and transmission (R, A and T) of the silicon solar cell. It acts to minimize reflectance and improves the overall efficiency of the solar cell. DLARC variation focuses on increasing absorption while decreasing reflection and transmission. The high refractive index of the hydrogenated a-Si (a-Si: H) emitter layer generates excessive reflection losses in SHJ solar cells making the silicon wafer have a low absorption efficiency. The DLARC thickness and base angle are varied as part of the simulation using the Wafer Ray Tracer by PV Lighthouse. The surface morphology of upright pyramid texture, height is 3.536 µm, texture base angle 54.74 °, and width 5 µm are used for reference scheme. Four schemes will be analyzed throughout this study along with the reference scheme. The result of this study is that Scheme 3 gives the optimum result with 99 % absorption, 21 % reflection and 67 % transmission. The goal of this study is to evaluate the impact of ARC thickness on optical and electrical characteristics. The best outcome is produced by varying the thickness and base angle of Scheme 3. The highest Jmax value, 0.3842 mA/cm2, is found in Scheme 3. HIGHLIGHTS The high refractive index of the hydrogenated a-Si (a-Si: H) emitter layer causes significant reflection losses in SHJ solar cells, resulting in a low absorption efficiency for the silicon wafer The double anti-reflection coating (DLARC) thickness and base angle are modified as part of the simulation using PV Lighthouse's Wafer Ray Tracer The best results are obtained by adjusting the thickness and base angle of Scheme 3. Scheme 3 has the highest Jmax value of 0.3842 mA/cm2 GRAPHICAL ABSTRACT

Influence of anti-reflection coatings on double GaAs/Si heterojunction layers in Si solar cells

In this work, a c-Si solar cell with double GaAs/Si heterojunction layers is simulated using PC1D simulation software. Optimization of the thickness and doping concentration of different layers of the solar cell is carried out. The impact of six different anti-reflection coatings (ARCs) on solar cell efficiency is investigated. Texturing of the front surface is carried out before studying the effect of ARCs. The simulation shows an increase in efficiency around 1.87% is achieved after applying an ARC of optimum thickness. Double-layer ARCs demonstrate a maximum efficiency of 17.41% in solar cells, which was about 15.54% without the coating. The effects of ARCs on the voltage, current, efficiency and reflectance are also studied in the wavelength range of 250 nm to 1200 nm. The maximum voltage, current and efficiency of the cells are achieved when the thicknesses of the ARCs are optimized at a wavelength of 600 nm.

TiO2/ZnO double-layer broadband antireflective and down-shifting coatings for solar applications

Making full use of sunlight in solar cells requires reducing the reflection of light and minimizing spectral mismatch. Here, a TiO2/ZnO double-layer coating with both wider band antireflection and down-shifting performance was prepared. TiO2 sols and ZnO nanoparticles were synthesized via the sol-gel method and then successively coated on the surface of the Si substrate by dip-coating. Computational simulations were used to obtain the optimal refractive index and thickness of the coatings. In the experiments, the thicknesses of the TiO2 and ZnO coatings were adjusted by changing the lifting speed, and the refractive index of the TiO2 and ZnO coatings were adjusted by adding the porosity inducing agent and varying the concentration of the solution. The TiO2/ZnO coating reduces the reflectivity of the silicon substrate by 24.97% in the 400–1100 nm band, and the ZnO nanoparticles can convert light at approximately 345 nm–527 nm, reducing the spectral mismatch of the solar cell. The photocurrent of solar cells coated with TiO2/ZnO coatings was markedly improved, with an increase of 29% in the average photocurrent at 300–800 nm. Herein, TiO2/ZnO coatings have the potential to benefit the development of multifunctional coatings that are important for improving the efficiency of solar cells.

Efficiency enhancement of ultrathin CIGS solar cells by optimal bandgap grading. Part II: finite-difference algorithm and double-layer antireflection coatings.

In Part I [Appl. Opt.58, 6067 (2019)APOPAI003-693510.1364/AO.58.006067], we used a coupled optoelectronic model to optimize a thin-film C u I n 1-ξ G a ξ S e 2 (CIGS) solar cell with a graded-bandgap photon-absorbing layer and a periodically corrugated backreflector. The increase in efficiency due to the periodic corrugation was found to be tiny and that, too, only for very thin CIGS layers. Also, it was predicted that linear bandgap-grading enhances the efficiency of the CIGS solar cells. However, a significant improvement in solar cell efficiency was found using a nonlinearly (sinusoidally) graded-bandgap CIGS photon-absorbing layer. The optoelectronic model comprised two submodels: optical and electrical. The electrical submodel applied the hybridizable discontinuous Galerkin (HDG) scheme directly to equations for the drift and diffusion of charge carriers. As our HDG scheme sometimes fails due to negative carrier densities arising during the solution process, we devised a new, to the best of our knowledge, computational scheme using the finite-difference method, which also reduces the overall computational cost of optimization. An unfortunate normalization error in the electrical submodel in Part I came to light. This normalization error did not change the overall conclusions reported in Part I; however, some specifics did change. The new algorithm for the electrical submodel is reported here along with updated numerical results. We re-optimized the solar cells containing a CIGS photon-absorbing layer with either (i)a homogeneous bandgap, (ii)a linearly graded bandgap, or (iii)a nonlinearly graded bandgap. Considering the meager increase in efficiency with the periodic corrugation and additional complexity in the fabrication process, we opted for a flat backreflector. The new algorithm is significantly faster than the previous algorithm. Our new results confirm efficiency enhancement of 84% (resp. 63%) when the thickness of the CIGS layer is 600nm (resp. 2200nm), similarly to Part I. A hundredfold concentration of sunlight can increase the efficiency by an additional 27%. Finally, the currently used 110-nm-thick layer of M g F 2 performs almost as well as optimal single- and double-layer antireflection coatings.

Simple Design of Double-Layer Antireflection Coating for Er-Doped Glass Laser Application

In an Erbium-doped glass laser resonator, parasitic light oscillations (yielding a lowering of the output laser beam power) may be avoided by deposition of well-adapted antireflection coatings on the edges of the active glass medium. However, towards laser application, efficient double-layers are scarce in literature. Here, we propose a simple design of double-layer (total thickness < 490nm) composed of thin films of MgF2 and Al2O3, materials that are easy to deposit by electron beam evaporation. Such coating design allows a calculated reflectance to be lower than 0.01% in the considered 1530-1570nm Near-Infrared range.

Numerical analysis of MgF2/SiO2 bilayers anti-reflective coating of light trapping in silicon solar cells by ray tracer software

Anti-reflective coating (ARC) application is continuously being developed extensively and widely for the manufacture of coatings on the surfaces of optical devices which are hugely essential, desirable, and required, particularly on silicon solar cells. Single layer ARC is sufficient, but double layer ARC tremendously enhances solar cell efficiency by covering a wider range of the solar spectrum. Magnesium fluoride, MgF2 and silicon dioxide, SiO2 are the ARC coatings used in this work, with wavelengths in the range from 300 to 1200 nm. The optical properties of bilayer ARC coatings were obtained by varying the thickness of the double coatings and see how the ARC effects Si solar cells. Wafer ray tracer was used in PV Lighthouse software to simulate and model MgF2 and SiO2 bilayer ARC coatings in order to fully understand the performance and impacts of the coatings on Si solar cells. This simulation work contains the analysis of reflection, absorption, transmission, and Jmax, which have been compared to many other theoretical results gathered from other studies and researches. To conclude, the absorption of the wavelength is highest between 500 nm to 900 nm leads to lowest reflection. The output shows that bilayer anti-reflective coatings with the thickness of 75 nm MgF2 and SiO2 are much more effective where the value of Jmax is reach 32.80 mA/cm2. The Jmax enhancement compare to reference is 27.13% is achieved.

Effect of multilayer anti-reflective coating on spectral emissivity of area blackbody

An area blackbody is used as a standard radiant source for calibrating equipment of non-contact infrared temperature measurement. Tailoring the spectral emissivity of area blackbody is important for improving the accuracy of a temperature measurement system. In this work, a new antireflective coating (ARC) has been proposed and the first association it with area blackbody has been made to improve the emission in the 3–14 μm wavelength range. We have compared the single, dual and triple-layer of different ARC materials with a different combination. In each category, we have optimized the SiO2, Al2O3 and Si3N4 thin films layer stack as ARC coating and then compared radiation property of area blackbody covered by ARC. Numerical simulations of the spectral emissivity of the combination reveals that double-layer ARC is taken as the most excellent stack structure, which can realize spectral emissivity exceeding 0.9 with least material in the wavelength range from 3 to 13 μm. Physical mechanisms responsible for the increasing emissivity are elucidated as due to producing the gradual variation of the refractive index and the selection of each layer material directly affects emission performance. Considering excellent radiation property of area blackbody combined with ARC, this study can help pave the way for designing ideal area blackbody.

Utilization of CaF2/ITO Double‐Layer Anti‐Reflective Coating for Increasing the Efficiency in Rear Emitter SHJ Solar Cells

AbstractA method to minimize optical losses in the front side of rear emitter silicon heterojunction (SHJ) solar cells by applying double‐layer antireflection coating (DLARC) has been examined. The primary aim is to increase the short circuit current density (Jsc) using DLARC that is associated with the cell's absorbance. The optical and electrical properties of single‐layer antireflection coating (SLARC) are studied and compared with calcium fluoride (CaF2)/Indium tin oxide (ITO) DLARC.OPAL 2 is utilized as a simulation tool to increase the optical properties of CaF2/ITO DLARC, and the experimental result verifies its validity. ITO is deposited using sputter system while thermal evaporator is utilized to deposit CaF2 to make DLARC. The SHJ solar cell having DLARC demonstrates the average reflection of 6.55% which is 31.7% less than SLARC, that is 9.59% for the wavelength range of 300 to 1100 nm. The fabricated textured solar cell with CaF2/ITO DLARC shows enhancement in external quantum efficiency from 76.89% to 81.06%. It also indicates an improvement in Jsc to 40.83 mA cm‐2 from 39.91 mA cm–2 and having a conversion efficiency of >21% when compared with that of ITO SLARC.

λ/4–λ/4 Double-Layer Broadband Antireflective Coatings with Constant High Transmittance

Antireflective (AR) coatings can suppress the undesired interfacial Fresnel reflections, and they are widely used in optical devices and energy-related instruments. Conventional single-layer AR coatings, which only work at a single wavelength, encounter serious limitations in some practical applications because of their inherent properties. In this paper, λ/4–λ/4 double-layer antireflective (AR) coatings with constant high transmittance in a pre-determined wavelength range was prepared by the sol–gel method via acid-catalyzed and base-catalyzed SiO2 thin films. A double-layer antireflective coating with an almost constant transmittance value of 99.8% in the range of 550–700 nm was obtained, and the transmittance of this coating was higher than 99% in a wider range of 450–850 nm with a fluctuation of less than 1%. The coatings had good environmental stability and maintained constant high transmittance after two weeks of exposure in 50% humidity. The broadband AR coatings may have important applications in fields such as electroluminescent display.

Design and Simulation of Triple Layer Antireflection Coating for Silicon Solar Cells

In present work an attempt has been made to investigate the effect of triple layer anti-reflection coating (TLARC) on the surface of silicon cell theoretically. In this regard, MgF2, Si3N4, and TiO2 have been used to design anti-reflection coatings (ARC). Reflection spectra for single double and triple layer ARCs have been evaluated numerically using transfer matrix method (TMM). Numerically calculated reflection spectra for single, double, and triple layer anti-reflection coatings further used in PC1D simulator to study the performance of silicon solar cell. Result shows reduction in reflectance of silicon solar cell down to less than 3% in the wavelength range 400 – 1200 nm with conversion efficiency 21.6% for TLARC (MgF2/Si3N4/TiO2).

Influence of Al2O3/IZO double-layer antireflective coating on the front side of rear emitter silicon heterojunction solar cell

Transparent conductive oxide (TCO) thin films play a significant role in silicon heterojunction (SHJ) solar cell and perform both as antireflection coating (ARC) and carrier transport layer. Indium zinc oxide (IZO) films have attracted much attention in opto-electronic industry as an alternative TCO material owing to their superior optical and electrical characteristics as compared to conventionally used indium tin oxide (ITO) films. The optical and electrical properties of IZO films were studied and compared with ITO films. Moreover, the dielectric layer of Al2O3 was deposited on the IZO films using an atomic layer deposition (ALD) system to prepare a double layer antireflection coating (DLARC) structure. The wafer ray tracer simulation tool was used to optimize the thickness of Al2O3/IZO DLARC for SHJ solar cells and experimental results showed its validation. The performance of Al2O3/IZO DLARC on the front surface of rear emitter SHJ solar cell recorded to increase in the current density of 1.37% with enhancement in the efficiency of 0.8%, showing noticeable improvement as compared to cell fabricated with single-layer IZO film.

Enhancing the efficiency and stability of Organic/Silicon solar cells using graphene electrode and Double-layer Anti-reflection coating

Silicon (Si) based organic/inorganic hybrid solar cells have attracted much attentions due to their low-temperature solution process and high power conversion efficiency (PCE). However, the use of metallic grids electrode impedes the efficient light absorption, and the hybrid solar cells still suffer from poor air stability. Here, we demonstrate the fabrication of high-efficiency, air stable organic/Si heterojunction solar cells by using a graphene transparent electrode as well as a double-layer anti-reflection coating (DL-ARC). The use of highly transparent graphene film could avoid the strong light blocking effect of conventional metallic grids electrode and ensure the effective carrier collection. Meantime, the light-harvesting of Si wafer is remarkably enhanced by the DL-ARC based on polymethyl methacrylate (PMMA) and Poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) stacking layer. The assembled organic/Si heterojunction devices present outstanding photovoltaic performance with a PCE as high as 13.01% under AM 1.5G irradiation. More importantly, thanks to the protective effect of graphene/PMMA layer, the devices exhibited an excellent stability, and 94% of the pristine efficiency could be maintained after storing in air for 4 months without any encapsulation. Our work paves the way towards the fabrication of hybrid solar cells with high performance and stability.

Optimization of Antireflection Coating Design Using PC1D Simulation for c − Si Solar Cell Application

Minimizing the photon losses by depositing an anti-reflection layer can increase the conversion efficiency of the solar cells. In this paper, the impact of anti-reflection coating (ARC) for enhancing the efficiency of silicon solar cells is presented. Initially, the refractive indices and reflectance of various ARC materials were computed numerically using the OPAL2 calculator. After which, the reflectance of SiO2,TiO2,SiNx with different refractive indices (n) were used for analyzing the performance of a silicon solar cells coated with these materials using PC1D simulator. SiNx and TiO2 as single-layer anti-reflection coating (SLARC) yielded a short circuit current density (Jsc) of 38.4 mA/cm2 and 38.09mA/cm2 respectively. Highest efficiency of 20.7% was obtained for the SiNx ARC layer with n=2.15. With Double-layer anti-reflection coating (DLARC), the Jsc improved by ∼0.5 mA/cm2 for SiO2/SiNx layer and hence the efficiency by 0.3%. Blue loss reduces significantly for the DLARC compared with SLARC and hence increase in Jsc by 1 mA/cm2 is observed. The Jsc values obtained is in good agreement with the reflectance values of the ARC layers. The solar cell with DLARC obtained from the study showed that improved conversion efficiency of 21.1% is obtained. Finally, it is essential to understand that the key parameters identified in this simulation study concerning the DLARC fabrication will make experimental validation faster and cheaper.

Selection of Materials for Double Layer Antireflection Coating of Silicon Solar Cell

In present work an attempt has been made to select material to design double layer antireflection coatings (DLARC) for silicon solar cell, theoretically. In this regard, silicon nitride (Si3N4) is used along with MgF2 and SiO2 to design DLARC to achieve zero reflectance over wide range of spectra. Reflection spectra for DLARC systems of MgF2/Si3N4 and SiO2/Si3N4 have been evaluated numerically using transfer matrix method (TMM). Further, reflectance for MgF2/Si3N4 is investigated at various monitoring wavelengths (o = 550, 600, 650 and 700 nm). Calculated reflectance has been used in PC1D simulator to study the effect of double layer antireflection coating on optical and electrical parameters of silicon solar cell. Simulation results shows, reduction in reflectance form > 30% down to zero in the wavelength range 500 – 700 nm with conversion efficiency 21.33% at 600 nm for MgF2/Si3N4.