Download or read book Micro and Macroscopic Characterization of Recombination Losses in High Efficiency Cu In Ga Se2 Thin Film Solar Cells written by Benjamin Bissig and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of Alkaline doped Wide Bandgap Chalcopyrite Cu In Ga Se2 Thin Films and Solar Cells written by Setareh Zahedi-Azad and published by . This book was released on 2020* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin-film solar cells, Cu(In,Ga)Se2, recombination, open-circuit voltage, efficiency, simulation.

Download or read book Optical Physics of Cu In Ga Se2 Solar Cells and Their Layer Components written by Abedl-Rahman Ibdah and published by . This book was released on 2016 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycrystalline Cu(In1-xGax)Se2 (CIGS) thin film technology has emerged as a promising candidate for low cost and high performance solar modules. The efficiency of CIGS solar cells is strongly influenced by several key factors. Among these factors include Ga composition and its profile in the absorber layer, copper content in this layer, and the solar cell multilayer structure. As a result, tools for the characterization of thin film CIGS solar cells and their layer components are becoming increasingly essential in research and manufacturing. Spectroscopic ellipsometry is a non-invasive technique that can serve as an accurate probe of component layer optical properties and multilayer structures, and can be applied as a diagnostic tool for real-time, in-line, and off-line monitoring and analysis in small area solar cell fabrication as well as in large area photovoltaics manufacturing. Implementation of spectroscopic ellipsometry provides unique insights into the properties of complete solar cell multilayer structures and their layer components. These insights can improve our understanding of solar cell structures, overcome challenges associated with solar cell fabrication, and assist in process monitoring and control on a production line. In this dissertation research, Cu(In,Ga)Se2 films with different Cu contents have been prepared by the one stage co-evaporation process. These films have been studied by real time spectroscopic ellipsometry (RTSE) during deposition, and by in-situ SE at the deposition temperature as well as at room temperature to extract the dielectric functions (e1, e2) of the thin film materials. Analytical expressions for the room temperature dielectric functions were developed, and the free parameters that describe these analytical functions were in turn expressed as functions of the Cu content. As a result of this parameterization, the dielectric function spectra (e1, e2) can be predicted for any desired composition within the range of the samples investigated. This capability was applied for mapping the structural and compositional variations of CIGS thin films deposited over a 10 cm × 10 cm substrate area. In another application presented in this dissertation, a non-invasive method utilizing ex-situ spectroscopic ellipsometry analysis has been developed and applied to determine non-destructively the Ga compositional profile in CIGS absorbers. The method employs parameterized dielectric function spectra (e1, e2) of CIGS versus Ga content to probe the compositional variation with depth into the absorber. In addition, a methodology for prediction of the external quantum efficiency (QE) including optical gains and losses for a CIGS solar cell has been developed. The methodology utilizes ex-situ spectroscopic ellipsometry analysis of a complete solar cell, with no free parameters, to deduce the multilayer solar cell structure non-invasively and simulate optical light absorption in each of the layer components. In the case of high efficiency CIGS solar cells, with minimal electronic losses, QE spectra are predicted from the sum of optical absorption in the active layer components. For such solar cells with ideal photo-generated charge carrier collection, the SE-predicted QE spectra are excellent representation of the measured ones. Since the QE spectra as well as the short circuit current density (Jsc) can be calculated directly from SE analysis results, then the predicted QE from SE can be compared with the experimental QE to evaluate electronic losses based on the difference between the spectra. Moreover, the calculated Jsc can be used as a key parameter for the design and optimization of anti-reflection coating structures. Because the long term production potential of CIGS solar modules may be limited by the availability of indium, it becomes important to reduce the thickness of the CIGS absorber layer. Thickness reduction would reduce the quantity of indium required for production which would in turn reduce costs. A decrease in short-circuit current density (Jsc) is expected, however, upon thinning the CIGS absorber due to incomplete absorption. To clarify the limits of obtainable Jsc in ultra-thin CIGS solar cells with Mo back contacts, optical properties and multilayer structural data are deduced via spectroscopic ellipsometry analysis and used to predict the QE spectra and maximum obtainable Jsc values upon thinning the absorber. Moreover, SE-guided optical design of ultra-thin CIGS solar cells has been demonstrated. In the case of solar cells fabricated on Mo, thinning the absorber in a CIGS solar cell is associated with significant optical losses in the Mo containing back contact layers. This is due in part to the poor optical reflectance of Mo. Such optical losses may be reduced by employing a back contact design with improved reflectance. Thus, alternative novel solar cell structures with ultra-thin absorbers and improved back contact reflectance have been designed and investigated using SE and the optical modeling methods. In addition to optical losses, electronic losses in the ultra-thin solar cells have been evaluated. By separating the absorber layer into sub-layer regions (for example, near-junction, bulk, and near-back-contact) and varying carrier collection probability in these regions, the contribution of each region to the current can be estimated. Based on this separation, the origin of the electronic losses has been identified as near the back contact.

Download or read book Coherent Optical Analysis of the ZnO CdS Cu In Ga Se 1tn2 Thin Film Solar Cell written by Kay Orgassa and published by . This book was released on 2004 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High efficiency Cu In Ga Se2 Thin Film Solar Cells Without Intermediate Buffer Layers written by Kannan Ramanathan and published by . This book was released on 1998 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microscopic Properties of Grain Boundaries in Cu In Ga Se2 and CuInS2 Thin film Solar Cells Studied by Transmission Electron Microscopy written by and published by . This book was released on 2011 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development Characterization and Modeling of CuGaSe2 Cu In Ga Se2 Thin film Tandem Solar Cells written by Jiyon Song and published by . This book was released on 2006 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spectrally Resolved Current Losses in Cu In Ga Se2 Thin film Solar Cells written by Jonas Lähnemann and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chalcogenide Photovoltaics written by Roland Scheer and published by John Wiley & Sons. This book was released on 2011-03-31 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first comprehensive description of the most important material properties and device aspects closes the gap between general books on solar cells and journal articles on chalcogenide-based photovoltaics. Written by two very renowned authors with years of practical experience in the field, the book covers II-VI and I-III-VI2 materials as well as energy conversion at heterojunctions. It also discusses the latest semiconductor heterojunction models and presents modern analysis concepts. Thin film technology is explained with an emphasis on current and future techniques for mass production, and the book closes with a compendium of failure analysis in photovoltaic thin film modules. With its overview of the semiconductor physics and technology needed, this practical book is ideal for students, researchers, and manufacturers, as well as for the growing number of engineers and researchers working in companies and institutes on chalcogenide photovoltaics.

Download or read book Nanoscale investigation of potential distribution in operating Cu In Ga Se2 thin film solar cells written by Zhenhao Zhang and published by KIT Scientific Publishing. This book was released on 2014-10-16 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: The distribution of the electrostatic potential in and between the materials in Cu(In,Ga)Se2 thin-film solar cells has a major impact on their superior performance. This thesis reported on the nanoscale imaging of the electrostatic potential on untreated cross sections of operating Cu(In,Ga)Se2 solar cells using Kelvin probe force microscopy.

Download or read book Preparation and Characterization of Cu In Ga Se2 Thin film Solar Cells and TiNb2O7 Anode Material for Lithium ion Batteries written by 歐長穎 and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimisation of Cu In Ga Se 1tn2 Thin Film Solar Cells and Modules for Low Irradiance Conditions written by Alessandro Virtuani and published by . This book was released on 2004 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Interface Modification by Ion Implantation and Optical Characterization of High efficiency Cu In Ga Se2 Solar Cells written by Jakob Haarstrich and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three different issues are discussed in this thesis, which aim for a deeper understanding of Cu(In,Ga)Se2 material properties and solar cell functionality: (1)Near-surface ion implantation in Cu(In,Ga)Se2 absorber layers is studied as a method for the fabrication of buffer-free solar cells. Simulations show the beneficial effect of an n-type surface layer (buried junction). To obtain an inversion by means of ion implantation, an annealing procedure is developed that avoids annealing-induced degradation of the cell, minimizes the diffusion of the ions, and recovers the implantation damage. Buffer-free solar cells made from implanted absorbers show strongly improved diode characteristics comparable to the ones of cells with a CdS buffer and a maximum efficiency of 10.2% (11.2% active area). (2)A model is developed for the application of luminescence techniques on band-gap graded semiconductor thin-films. Several DA-emissions are detected in the cathodoluminescence (CL) and photoluminescence (PL) spectra of Ga-graded in Cu(In,Ga)Se2 and related to the local Ga-contents in the layer. The depth-distribution of the luminescence signal is correlated to the band-gap profile. Drift of excited charge carriers towards the band-gap minimum is caused by the grading-induced quasi-electric field, which must be considered when explaining the spectra obtained in plan-view measurements. Monochromatic CL imaging on cross-sections is capable to determine the minority carrier mobility.

Download or read book On Generation and Recombination in Cu In Ga Se2 Thin film Solar Cells written by and published by . This book was released on 2005 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of Microstructural and Chemical Features in Cu In Ga Se S based Thin film Solar Cells written by Ankush R. Halbe and published by . This book was released on 2006 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: For a sample with a transparent back contact, a 10 nm Mo layer was deposited on ITO (indium tin oxide) before deposition of the CIGS2 (Cu(In,Ga)S2) layer. EFTEM maps indicate that a MoS2 layer does not form for such a Mo/MoS2-ITO back contact. Instead, absorber layer material diffuses through the thin Mo layer onto the ITO forming two layers of CIGS2 on either side of Mo with different compositions.

Download or read book Enhancement of the Deposition Processes of Cu In Ga Se2 and Cds Thin Films Via In situ and Ex situ Measurements for Solar Cell Application written by Vikash Ranjan and published by . This book was released on 2011 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin films of Cu(In, Ga)Se2 deposited by 1-stage, 2-stage and 3-stage co-evaporation processes result into the highest efficiency solar cells. Controlling the rate and sequences of individual sources during these co-evaporation processes are important for better quality Cu(In, Ga)Se2 absorber layers. At the same time, spectroscopic ellipsometry due to its ex-situ as well as in-situ application is considered as a very powerful tool to understand the material properties as well as to monitor the process. Nevertheless, spectroscopic ellipsometry was not properly utilized until now to characterize Cu(In, Ga)Se2 thin films. In this study, one of our goal is to understand the optical and electrical properties of Cu(In, Ga)Se2 as a function of process and composition. In the first part of this study, we implemented ex-situ spectroscopic ellipsometry (SE) along with other characterization techniques like Secondary ion mass spectroscopy (SIMS), Scanning electron microscopy (SEM), Auger electron spectroscopy (AES), x-ray diffraction (XRD), atomic force microscopy (AFM) etc. to compare Cu(In, Ga)Se2 thin films deposited by the above mentioned three co-evaporation processes. During this study, we were able to use SE to find the thickness, roughness, band gap, Ga grading of the Cu(In, Ga)Se2 deposited by 2-stage and 3-stage process. Finding of SE were correlated by SIMS, AES, SEM etc. In the case of Cu(In, Ga)Se2 deposited by 1-stage process, due to the high surface roughness, we are not able to implement the ex-situ spectroscopic ellipsometry. In the second and third part of this study, real time spectroscopic ellipsometry is implemented to study the material properties of Cu(In, Ga)Se2 thin films as a function of Cu and Ga concentration. Effectively, in a 3-stage co-evaporation process, the composition of the film changes during the process. To monitor and control the composition of Cu(In, Ga)Se2 during the 3-stage process by in-situ ellipsometry, it was necessary to understand the optical properties of Cu(In, Ga)Se2 as a function of Cu atomic percentage (at.%) as well as Ga at.%. Along with this, the inability to implement ex-situ SE for Cu(In, Ga)Se2 thin film motivated us to implement the spectroscopic ellipsometry in real time i.e. during the growth of the film. This in-situ real time application of SE helped us in understanding the micostructural evolution and dependence of the band gap with the Cu atomic percentage (at.%) as well as the Ga at.%. We also used this opportunity to understand the shift in the critical points as a function of temperature for CuInSe2 alloys. Characterization like AES, XRD, AFM etc were performed after the growth at room temperature to corroborate the RTSE findings. In the fourth and last part of this study, the growth of CdS on a Cu(In, Ga)Se2 surface as a function of time was studied using SE as well as AFM. We also used this opportunity to compare the growth of CdS on another substrate (SiO2). Spectroscopic ellipsometry and AFM revealed a quantum confinement effect in the case of CdS on SiO2 whereas no such effect was observed for CdS on Cu(In, Ga)Se2 surface due to the growth of compact CdS layers.

Download or read book Modeling and Simulation of Charge Carrier Recombination Dynamics in Cu In Ga Se2 Thin Film Solar Cells written by José Fabio López Salas and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solar cells with thin Cu(In,Ga)(S,Se)2 absorber films are well established in the photovoltaics market. They offer an advantage over other thin film technologies thanks to their lower content of elements with high toxicity or low earth abundance like Cd and Te. One approach to further improve the quality of production of these cells is to develop a method of material quality assessment during production that is fast, contactless and non-destructive. Time-resolved photoluminescence (TRPL) measurements offer all these characteristics. This work aims to establish the requirements to extract meaningful information about charge carrier recombination dynamics and solar cell performance parameters from TRPL measurements. To achieve this goal experiments and simulations are carried out. The material parameters are extracted from experiments and then built into the simulation model. Results from experiments also serve as the basis to verify the validity of this model. Parameter variations within the simulations function as one of the main methods in this work to gain deeper physical insight into the processes taking place during TRPL measurements. engl.