Search results for "photovoltaicS"
showing 10 items of 178 documents
Performance Analysis of a Prototype High‐Concentration Photovoltaic System Coupled to Silica Optical Fibers
2021
High-concentration photovoltaic (HCPV) systems are one of the most promising technologies for the generation of renewable energy with high-conversion efficiency. Their development is still at an early stage, but the possibility of integrating high-concentration systems into buildings offers new opportunities to achieve the net-zero-energy building goal. Herein, the optical and energetic performance of a hybrid daylighting−HCPV prototype based on pure- or doped-silica optical fibers (OFs) to guide 2000× concentrated sunlight inside the buildings is evaluated. There, the light can either be used to illuminate interior spaces or projected on solar cells to generate electricity. The system equi…
Polymer solar cells with novel fullerene-based acceptor
2004
Abstract Alternative acceptor materials are possible candidates to improve the optical absorption and/or the open circuit voltage of polymer–fullerene solar cells. We studied a novel fullerene-type acceptor, DPM-12, for application in polymer–fullerene bulk heterojunction photovoltaic devices. Though DPM-12 has the identical redox potentials as methanofullerene PCBM, surprisingly high open circuit voltages in the range V OC =0.95 V were measured for OC 1 C 10 -PPV:DPM-12-based samples. The potential for photovoltaic application was studied by means of photovoltaic characterization of solar cells including current–voltage measurements and external quantum yield spectroscopy. Further studies …
Enhanced Efficiency of Organic Solar Cells by Thiol-capped Au-Nanoparticles
2015
In this work, we present a study on the effect of thiol-capped AuNPs of various sizesin an organic solar cell.AuNPs have been obtained by laser ablation in liquid solution[2], have been functionalized both with 2-naphthalenethiol and alkanethiol having different length. In addition to bulk heterojunction structures with optimized interpenetrating network of donors and acceptor domains, we have chosen to study planar heterojunctions (PHJs), consisting of three component thin films realized by sequential deposition of P3HT, AuNPs and PCBM from orthogonal solvents.
Direct measurement of optical losses in plasmon-enhanced thin silicon films (Conference Presentation)
2018
Plasmon-enhanced absorption, often considered as a promising solution for efficient light trapping in thin film silicon solar cells, suffers from pronounced optical losses i.e. parasitic absorption, which do not contribute to the obtainable photocurrent. Direct measurements of such losses are therefore essential to optimize the design of plasmonic nanostructures and supporting layers. Importantly, contributions of useful and parasitic absorption cannot be measured separately with commonly used optical spectrophotometry. In this study we apply a novel strategy consisting in a combination of photocurrent and photothermal spectroscopic techniques to experimentally quantify the trade-off betwee…
Polymer Halide Perovskites-Waveguides Integrated in Nanocellulose as a Wearable Amplifier-Photodetector System
2018
Semiconductor organometallic halide (CH 3 NH 3 PbX 3 , X=Cl, Br, I) perovskites (MHP) have emerged as a very high promising material for optoelectronics. Their large absorption coefficients, high electronic mobilities, excellent quantum yield of emission at room temperature and tunable band-gap with the composition resulted in a new generation of photovoltaics and electronic devices. In this work, HPVK materials are successfully incorporated on a nanocellulose (NC) substrate with the intention to exploit the interesting properties of HPVK materials to construct wearable devices. In particular, a bilayer Poly(methyl methacrylate) /HPVK deposited on NC resulted in a suitable waveguide to demo…
Potential and limitations of CsBi3I10 as a photovoltaic material
2020
Herein we demonstrate the dry synthesis of CsBi3I10 both as a free-standing material and in the form of homogeneous thin films, deposited by thermal vacuum deposition. Chemical and optical characterization shows high thermal stability, phase purity, and photoluminescence centered at 700 nm, corresponding to a bandgap of 1.77 eV. These characteristics make CsBi3I10 a promising low-toxicity material for wide bandgap photovoltaics. Nevertheless, the performance of this material as a semiconductor in solar cells remains rather limited, which can be at least partially ascribed to a low charge carrier mobility, as determined from pulsed-radiolysis time-resolved microwave conductivity. Further dev…
Color Tuning and White Light by Dispersing CdSe, CdTe, and CdS in PMMA Nanocomposite Waveguides
2013
In this paper, active nanocomposite waveguides based on the dispersion of CdS, CdTe, and CdSe colloidal quantum dots (QDs) in PMMA are proposed. Their propagation properties are studied as a function of the concentration of nanoparticles in the polymer using the variable length stripe method. When the three nanostructures are dispersed in the same film, the structure is able to waveguide the three basic colors: red (CdSe), green (CdTe), and blue (CdS), it being possible to engineer any waveguided color by an appropriate choice of the filling factor of each QD in the PMMA matrix. For this purpose, it is important to take into account reabsorption effects and the Förster energy transfe…
Si:O Alloys for Photovoltaics: Optical and Electrical Properties from Quantum Dots to Thin Films
2010
In current Si based PV devices the sun-light-electricity conversion rarely exceeds the 20% in efficiency, stimulating significant efforts towards new solutions and technologies for giving a boost to Si for PV. One of the most promising routes for the 21st century is exploiting the quantum confinement effect in reduced dimensionality systems, with the aim to harvest the full solar spectrum. Recently, it has been proposed that a certain modulation of the optical bandgap (EG OPT) can be attained by changing the size of Si quantum dots (QDs), which should allow for a large absorption of the solar photon flux [1]. By this way, an all-Si tandem solar cell could be fabricated, by stacking solar …
Photovoltaic characterization of organic solar cells
2018
In recent years organic solar cells (SCs) have reached power conversion efficiencies above 10% [1]. Organic photovoltaics is indeed an intensively pursued research field because it promises high efficiency and low cost SCs. Organic materials have unique and useful optoelectronic properties, their chemical synthesis can be cheap and easy, and can be deposited in the form of thin films even on flexible plastic substrates by simple deposition techniques such as spinning, ink-jet printing and high vacuum thermal evaporation. Here we report results of the photovoltaic characterization of organic SCs having the donor (D)/acceptor (A) heterojunction structure [2]. The SCs, fabricated by vacuum the…