Plasmonic and Photonic Designs for Light Trapping in Thin Film Solar Cells - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Plasmonic and Photonic Designs for Light Trapping in Thin Film Solar Cells write by Liming Ji. This book was released on 2012. Plasmonic and Photonic Designs for Light Trapping in Thin Film Solar Cells available in PDF, EPUB and Kindle. Thin film solar cells are promising to realize cheap solar energy. Compared to conventional wafer cells, they can reduce the use of semiconductor material by 90%. The efficiency of thin film solar cells, however, is limited due to insufficient light absorption. Sufficient light absorption at the bandgap of semiconductor requires a light path more than 10x the thickness of the semiconductor. Advanced designs for light trapping are necessary for solar cells to absorb sufficient light within a limited volume of semiconductor. The goal is to convert the incident light into a trapped mode in the semiconductor layer. In this dissertation, a critical review of currently used methods for light trapping in solar cells is presented. The disadvantage of each design is pointed out including insufficient enhancement, undesired optical loss and undesired loss in carrier transport. The focus of the dissertation is light trapping by plasmonic and photonic structures in thin film Si solar cells. The performance of light trapping by plasmonic structures is dependent on the efficiency of photon radiation from plasmonic structures. The theory of antenna radiation is used to study the radiation by plasmonic structures. In order to achieve efficient photon radiation at a plasmonic resonance, a proper distribution of surface charges is necessary. The planar fishnet structure is proposed as a substitution for plasmonic particles. Large particles are required in order to resonate at the bandgap of semiconductor material. Hence, the resulting overall thickness of solar cells with large particles is large. Instead, the resonance of fishnet structure can be tuned without affecting the overall cell thickness. Numerical simulation shows that the enhancement of light absorption in the active layer is over 10x compared to the same cell without fishnet. Photons radiated from the resonating fishnet structure travel in multiple directions within the semiconductor layer. There is enhanced field localization due to interference. The short circuit current was enhanced by 13.29%. Photonic structures such as nanodomes and gratings are studied. Compared to existing designs, photonic structures studied in this dissertation exhibited further improvements in light absorption and carrier transport. The nanodome geometry was combined with conductive charge collectors in order to perform simultaneous enhancement in optics and carrier transport. Despite the increased volume of semiconductor material, the collection length for carriers is less than the diffusion length for minority carriers. The nanodome geometry can be used in the back end and the front end of solar cells. A blazed grating structure made of transparent conductive oxide serves as the back passivation layer while enhancing light absorption. The surface area of the absorber is increased by only 15%, indicating a limited increase in surface recombination. The resulting short circuit current is enhanced by over 20%. The designs presented in the dissertation have demonstrated enhancement in Si thin film solar cells. The enhancement is achieved without hurting carrier transport in solar cells. As a result, the enhancement in light absorption can efficiently convert to the enhancement in cell efficiency. The fabrication of the proposed designs in this dissertation involves expensive process such as electron beam lithography. Future work is focused on optical designs that are feasible for cheap fabrication process. The designs studied in this dissertation can serve as prototype designs for future work.
Introduction to Light Trapping in Solar Cell and Photo-detector Devices
Introduction to Light Trapping in Solar Cell and Photo-detector Devices - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Introduction to Light Trapping in Solar Cell and Photo-detector Devices write by Stephen J. Fonash. This book was released on 2014-09-15. Introduction to Light Trapping in Solar Cell and Photo-detector Devices available in PDF, EPUB and Kindle. New Approaches to Light Trapping in Solar Cell Devices discusses in detail the use of photonic and plasmonic effects for light trapping in solar cells. It compares and contrasts texturing, the current method of light-trapping design in solar cells, with emerging approaches employing photonic and plasmonic phenomena. These new light trapping methods reduce the amount of absorber required in a solar cell, promising significant cost reduction and efficiency. This book highlights potential advantages of photonics and plasmonics and describes design optimization using computer modeling of these approaches. Its discussion of ultimate efficiency possibilities in solar cells is grounded in a review of the Shockley-Queisser analysis; this includes an in-depth examination of recent analyses building on that seminal work.
Diffractive Optics for Thin-Film Silicon Solar Cells
Diffractive Optics for Thin-Film Silicon Solar Cells - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Diffractive Optics for Thin-Film Silicon Solar Cells write by Christian Stefano Schuster. This book was released on 2016-09-26. Diffractive Optics for Thin-Film Silicon Solar Cells available in PDF, EPUB and Kindle. This thesis introduces a figure of merit for light trapping with photonic nanostructures and shows how different light trapping methods compare, irrespective of material, absorber thickness or type of nanostructure. It provides an overview of the essential aspects of light trapping, offering a solid basis for future designs. Light trapping with photonic nanostructures is a powerful method of increasing the absorption in thin film solar cells. Many light trapping methods have been studied, but to date there has been no comprehensive figure of merit to compare these different methods quantitatively. This comparison allows us to establish important design rules for highly performing structures; one such rule is the structuring of the absorber layer from both sides, for which the authors introduce a novel and simple layer-transfer technique. A closely related issue is the question of plasmonic vs. dielectric nanostructures; the authors present an experimental demonstration, aided by a detailed theoretical assessment, highlighting the importance of considering the multipass nature of light trapping in a thin film, which is an essential effect that has been neglected in previous work and which allows us to quantify the parasitic losses.
Nanostructured Solar Cells
Nanostructured Solar Cells - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Nanostructured Solar Cells write by Narottam Das. This book was released on 2017-02-22. Nanostructured Solar Cells available in PDF, EPUB and Kindle. Nanostructured solar cells are very important in renewable energy sector as well as in environmental aspects, because it is environment friendly. The nano-grating structures (such as triangular or conical shaped) have a gradual change in refractive index which acts as a multilayer antireflective coating that is leading to reduced light reflection losses over broadband ranges of wavelength and angle of incidence. There are different types of losses in solar cells that always reduce the conversion efficiency, but the light reflection loss is the most important factor that decreases the conversion efficiency of solar cells significantly. The antireflective coating is an optical coating which is applied to the surface of lenses or any optical devices to reduce the light reflection losses. This coating assists for the light trapping capturing capacity or improves the efficiency of optical devices, such as lenses or solar cells. Hence, the multilayer antireflective coatings can reduce the light reflection losses and increases the conversion efficiency of nanostructured solar cells.
Light Trapping in Thin-Film Silicon Solar Cells Via Plasmonic Metal Nanoparticles
Light Trapping in Thin-Film Silicon Solar Cells Via Plasmonic Metal Nanoparticles - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Light Trapping in Thin-Film Silicon Solar Cells Via Plasmonic Metal Nanoparticles write by Ryan Veenkamp. This book was released on 2014. Light Trapping in Thin-Film Silicon Solar Cells Via Plasmonic Metal Nanoparticles available in PDF, EPUB and Kindle.
