Plasmonic effects of au/ag bimetallic multispiked nanoparticles for photovoltaic applications (original) (raw)

Ag-encapsulated Au plasmonic nanorods for enhanced dye-sensitized solar cell performance

J. Mater. Chem. A, 2015

In this article, the Ag-encapsulated Au nanorods (Au@Ag NRs) are prepared and introduced into dye-sensitized solar cells (DSSCs). As a unique plasmonic nanostructure, this composite exhibit the superiorities on enhancing light-harvesting as well as restraining charge recombination of DSSCs. Remarkably enhanced light absorption of photoanode can be obtained via the Surface Plasmon Resonance (SPR) effect of the Au@Ag NRs, meanwhile a broadened absorption in the red and near-infrared (NIR) region ensures the full utilization of the solar energy. Beyond the dominated optical utility, the presence of the Au@Ag NRs promotes the suppression of the charge 10 recombination, further enhancing the photochemical catalysis of DSSCs. The optimized Au@Ag NR modified DSSC is achieved with the power conversion efficiency of 8.43%, which is significantly superior to that of the pure TiO 2 DSSC with the PCE of 5.91%.

Influence of Ag nanoparticles microstructure on their optical and plasmonic properties for photovoltaic applications

Solar Energy, 2017

This paper shows an experimental attempt to approach plasmonic structure of silver nanoparticles (NPs) for photovoltaic application optimized previously for front side of thin film silicon solar cells. For that purpose the synthesis of high concentration of 100 and 140 nm Ag nanoparticles suspensions and layer-by-layer deposition method was applied. The results of electrical and optical studies of silicon solar cells with Ag nanoparticles as well as the microstructure of nanoparticles assemblies examined by SEM are presented. The results of these measurements are compared with theoretically predicted ones for optimized case and are the basis for further simulation analysis of the influence of the microstructure of actual nanoparticles assemblies. The simulations cover particles size distribution, the presence of agglomerates and arrangement. The results of these simulations show that the microstructure parameters decide on the plasmonic properties leading to the limited cell performance enhancement. Here we present more than 12% increase of short circuit current density and perspectives for further improvement. The outcomes of these studies have a general character and should be considered for optimization of other plasmonic structures used in photovoltaic and optoelectronic devices.

Localized surface plasmon resonance on Au nanoparticles: tuning and exploitation for performance enhancement in ultrathin photovoltaics

We report a detailed correlation analysis of the size, shape, and distribution of Au nanoparticles (NPs) on fine-tuning of localized surface plasmon resonance and optical absorption cross-section. Experimental analysis of annealing temperature and initial Au layer thickness on NP parameters such as size, interparticle distance, surface coverage, and circularity factor has been studied. The effect of annealing on the morphological, structural, dielectric, and elemental behavior of Au NPs has been reported. Theoretically, we have analyzed the tuning of LSPR and absorption cross-section peaks by varying NP parameters, surrounding medium, and substrate. This report is critical in terms of predicting performance enhancement of ultrathin photovoltaics with varied cell architectures.

Au/Ag Bimetallic Nanocomposites as a Highly Sensitive Plasmonic Material

Plasmonics, 2018

We report Au/Ag bimetallic nanocomposites as a highly sensitive plasmonic material. A unit approach via a three-dimensional numerical modeling is introduced to observe collective plasmon resonance in Au/Ag bimetallic nanocomposites as well as Au mono-metallic nanoensembles. Au nanoensembles provide consistently identical plasmon wavelength, independent of inter-unit distance. In analogy with mono-metallic nanoensembles, Au/Ag bimetallic nanocomposites distinctly feature converging dual plasmon resonance peaks to a single plasmon resonance peak, strongly depending on the packing density and the unit size. An effective unit size of bimetallic nanocomposites is below 2.5 nm in a subwavelength structure, which is small enough to feature bimetallic nanocomposites. As a result, the Au/Ag bimetallic nanocomposites clearly show exceptionally high sensitivity and figure-ofmerit (approximately 3 fold of conventional plasmon sensitivity and 4.3 fold of conventional plasmon FOM), resulting from coupled Au-Ag quadrupole bimetallic nanounits. This study provides essential rationales for Au/Ag bimetallic nanocomposites serving as a desirable and alternative plasmonic material for advanced nanoplasmonic sensing technologies.

Ambient-dependent Agglomeration and Surface-Enhanced Raman Spectroscopy Response of Self-Assembled Silver Nano-particles for Plasmonic Photovoltaic Devices

The agglomeration/dewetting process of thin silver films provides a scalable method of obtaining self-assembled nanoparticles (SANPs) for plasmonics based thin-film solar photovoltaic (PV) devices. Here, we show the effect of annealing ambiance on silver SANP average size, particle/cluster finite shape, substrate area coverage/particle distribution and how these physical parameters influence optical properties and surface-enhanced Raman scattering (SERS) responses of SANPs. Statistical analysis performed indicates that generally Ag SANPs processed in the presence of a gas (Argon and Nitrogen) ambiance tend to have smaller average size particles compared to those processed under vacuum. Optical properties are observed to be highly dependent on particle size, separation distance as well as finite shape. The greatest SERS enhancement was observed for the argon processed samples. There is a correlation between simulation and experimental data that indicate argon processed AgNPs have a great potential to enhance light coupling when integrated to thin-film PV. 1 Introduction As-deposited thin metallic films are generally metastable or unstable and readily de-wet from a solid substrate when heated even well below their melting temperature 1-2. The process of agglomeration/de-wetting proceeds in two ways: nucleation and growth of holes, and spinodal dewetting 1, 3-5. This process is a relatively economical means of obtaining both simple and complex nano-structures from thin metal films 5-10 compared to traditional methods such as e-beam lithography. Whilst dewetting during film processing has been reported to have undesirable effects on micro-and nano-systems, agglomeration has become the method of choice for catalyzed growth of nanotubes/nanowires and electronic and photonic devices 3. Dewetting of thin metallic films (both liquid and solid) to obtain mono/multi-dispersed nanoparticles has been demonstrated with a range of metals including: gold (Au), silver (Ag), nickel (Ni), copper (Cu) and alumina (Al), among others 1, 3-4, 10-1. However, Ag film dewetting has been mostly investigated as candidate for plasmonic sensing 12-18 and plasmonics-enhanced solar photovoltaics (PV) devices 19-31 applications. This is because Ag is generally considered to have the most suitable optical properties for solar cell applications. Silver nanoparticles exhibit highly intense and localized surface plasmon resonances (LSPR) and low absorption in the visible and near

Plasmonic properties of Au-Ag nanoparticles: Distinctiveness of metal arrangements by optical study

Journal of Applied Physics, 2014

The core-shell arrangement of binary compound plasmonic nanoparticles (NPs) is usually verified by plasmonic extinction spectra, since microscopy-based methods cannot provide analysis of many NPs. Here, we discuss possible scenarios of different metal arrangements: (i) core-shell model, (ii) bimetallic model, and (iii) mixture of pure metal NPs. The possibility of distinguishing individual cases is discussed in accordance with numerical simulations and an alternative characterization is suggested. V

Comparative study of Au and Ag nanoparticle to improved in absorption in plasmonic solar cell

2017 Devices for Integrated Circuit (DevIC), 2017

Improving the photon absorption in thin-film solar cells with plasmonic nanoparticles is essential for the realization of extremely efficient cells with substantial cost reduction. Here, a comprehensive study of solar energy enhancement in a cadmium telluride (CdTe) thin-film solar cell based on the simple design of a square array of plasmonic titanium nanoparticles, has been reported. The excitation of localized plasmons in the metallic nanostructures together with the antireflection coating (ARC) significantly enhances the absorption of photons in the active CdTe layer. The proposed structure attained super absorption with a mean absorbance of more than 97.27% covering a wide range from visible to nearinfrared (i.e., from 300 nm to 1200 nm), presenting a 90% absorption bandwidth over 900 nm, and the peak absorption is up to 99.9%. For qualitative analysis, the photocurrent density is also estimated for AM 1.5 solar illumination (global tilt), whose value reaches 40.36 mA cm À2 , indicating the highest value reported to date. The impact of nanoparticle dimensions, various metal materials, shapes, and random arrangement of nanoparticles on optical absorption are discussed in detail. Moreover, the angle insensitivity is essentially validated by examining the absorption performance with oblique incidences and it is found that the solar cell keeps high absorption efficiency even when the incidence angle is greater than 0. Therefore, these findings suggest that the proposed broadband structure has good prospect in attaining high power conversion efficiency while reducing the device cost.

Plasmon-enhanced optical absorption and photocurrent in organic bulk heterojunction photovoltaic devices using self-assembled layer of silver nanoparticles

Solar Energy Materials and Solar Cells, 2010

Improved optical absorption and photocurrent for polythiophene-fullerene bulk heterojunction photovoltaic devices is demonstrated using a unique self-assembled monolayer of Ag nanoparticles formed from a colloidal solution. With the presence of suitable nanoparticle organic capping groups that inhibit its propensity to agglomerate, the particle-to-particle spacing can be tailored. Transmission electron microscopy reveals the self-assembled Ag nanospheres are highly uniform with an average diameter of 4nmandcontrollableparticle−to−particlespacing.Thelocalizedsurfaceplasmonresonancepeakis4 nm and controllable particle-to-particle spacing. The localized surface plasmon resonance peak is 4nmandcontrollableparticletoparticlespacing.Thelocalizedsurfaceplasmonresonancepeakis465 nm with a narrow full width at half maximum (95 nm). In the spectral range of 350-650 nm, where the organic bulk heterojunction photoactive film absorbs, an enhanced optical absorption is observed due to the increased electric field in the photoactive layer by excited localized surface plasmons within the Ag nanospheres. Under the short-circuit condition, the induced photocurrent efficiency (IPCE) measurement demonstrates that the maximum IPCE increased to 51.651.6% at 500 nm for the experimental devices with the self-assembled layer of Ag nanoparticles, while the IPCE of the reference devices without the plasmon-active Ag nanoparticles is 51.645.7% at 480 nm. For the experimental devices under air mass 1.5 global filtered illuminations with incident intensity of 100 mW/ cm 2 , the increased short-circuit current density is observed due to the enhancement of the photogeneration of excitons near the plasmon resonance of the Ag nanoparticles.