Author: Debora Regula KellerPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Role of Nanoscale Inhomogeneities in Cu(In,Ga)Se2 Thin Film Solar Cells
Author: Debora Regula KellerNanoscale investigation of potential distribution in operating Cu(In,Ga)Se2 thin-film solar cells
Author: Zhenhao ZhangPublisher: KIT Scientific Publishing
ISBN: 386644978X
Category : Science
Languages : en
Pages : 190
Book Description
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.
Thin Film Solar Cells From Earth Abundant Materials
Author: Subba Ramaiah KodigalaPublisher: Newnes
ISBN: 0123971829
Category : Technology & Engineering
Languages : en
Pages : 197
Book Description
The fundamental concept of the book is to explain how to make thin film solar cells from the abundant solar energy materials by low cost. The proper and optimized growth conditions are very essential while sandwiching thin films to make solar cell otherwise secondary phases play a role to undermine the working function of solar cells. The book illustrates growth and characterization of Cu2ZnSn(S1-xSex)4 thin film absorbers and their solar cells. The fabrication process of absorber layers by either vacuum or non-vacuum process is readily elaborated in the book, which helps for further development of cells. The characterization analyses such as XPS, XRD, SEM, AFM etc., lead to tailor the physical properties of the absorber layers to fit well for the solar cells. The role of secondary phases such as ZnS, Cu2-xS,SnS etc., which are determined by XPS, XRD or Raman, in the absorber layers is promptly discussed. The optical spectroscopy analysis, which finds band gap, optical constants of the films, is mentioned in the book. The electrical properties of the absorbers deal the influence of substrates, growth temperature, impurities, secondary phases etc. The low temperature I-V and C-V measurements of Cu2ZnSn(S1-xSex)4 thin film solar cells are clearly described. The solar cell parameters such as efficiency, fill factor, series resistance, parallel resistance provide handful information to understand the mechanism of physics of thin film solar cells in the book. The band structure, which supports to adjust interface states at the p-n junction of the solar cells is given. On the other hand the role of window layers with the solar cells is discussed. The simulation of theoretical efficiency of Cu2ZnSn(S1-xSex)4 thin film solar cells explains how much efficiency can be experimentally extracted from the cells. One of the first books exploring how to conduct research on thin film solar cells, including reducing costs Detailed instructions on conducting research
Nanoscale Investigation of Potential Distribution in Operating Cu(In,Ga)Se2 Thin-film Solar Cells
Author: Zhenhao ZhangKey Developments In CuInGaSe2 Thin Film Solar Cell
Author: Daniele MenossiPublisher: LAP Lambert Academic Publishing
ISBN: 9783659334498
Category :
Languages : en
Pages : 212
Book Description
Nowadays, thin-film solar cells potentially offer a suitable technology for solving the energy production problem with an environmentally friendly method. Besides, thin film technologies show advantages over their bulk-semiconductor counterparts due to their lighter weight, flexible shape and device fabrication schemes and low cost in large-scale industrial production. Although many books currently exist on general concepts of PV materials and devices, few are offering a comprehensive overview of the fast development in thin film Cu(In, Ga)Se2-based solar cells. "Key Developments in CuInGaSe2 Thin Film Solar Cell" would provide an international perspective on the latest research on this topic. It presents a wide range of scientific and technological aspects on basic properties and device physics of high-efficiency CIGS solar cells from the last research frontier point of view. The book was designed for photovoltaic researchers and scientists, students and engineers, with the mission to provide knowledge of the mechanisms, materials, devices, and applications of CIGS-based technology necessary to develop cheaper and cleaner renewable energy in the coming years.
High Performance Thin Film Solar Cells Via Nanoscale Interface
Author: Yao-Tsung HsiehPublisher:
ISBN:
Category :
Languages : en
Pages : 137
Book Description
It has been 64 years since Bell Laboratories built the first silicon solar cell in 1954. The harnessing of the almost unlimited energy from the sun for human civilization seems not an untouchable dream anymore. However, the rapid growth of the global population companied with the growing demand to enable a decent life quality causes the energy issue more challenging than ever. Nowadays silicon solar cells continue to take a leading position, not only offering potential solutions for energy demands but also stimulating the development of various photovoltaic technologies. Among them, solution processible thin film solar cells attract most attentions due to multiple advantages over traditional silicon solar cells. In this dissertation, I focus on two most promising types of them: 1) kesterite solar cells and 2) hybrid organic-inorganic perovskite solar cells. Particularly I work on the grain growth mechanism and processing techniques via nanoscale interface engineering to improve materials thin film properties and device architecture design. In Chapter 3, Cu2ZnSn(S,Se)4 was used as a model system to demonstrate the kinetic control of solid-gas reactions at nanoscale by manipulating the surface chemistry of both sol-gel nanoparticles and colloidal nanocrystals. It was identified that thiourea (commonly used as sulfur sources for metal sulfides) can transform to melamine during the film formation, and melamine would serve as surface ligands for as-formed Cu2ZnSn(S,Se)4 nanoparticles. These surface ligands can affect the solid-gas reactions during the selenization, which enable us to control film morphologies and device performance by simply adjusting the amount of surface ligands. To further enhance Cu2ZnSn(S,Se)4 device performance, a systematic investigation on alkali metal doping effect was conducted. In Chapter 4, alkali metal-containing precursors were used to study influences on Cu2ZnSn(S,Se)4 film morphology, crystallinity and electronic properties. K-doped Cu2ZnSn(S,Se)4 solar cells showed the best device performance. Due to the surface electronic inversion effect, various thickness of CdS buffer layers were tested on K-passivated Cu2ZnSn(S,Se)4 surface for further improving device efficiency. Over 8% power conversion efficiency of K-doped Cu2ZnSn(S,Se)4 solar cell with 35 nm CdS has been reached. Finally, in Chapter 5, the hybrid organic-inorganic perovskite solar cells are introduced. We demonstrated a novel tandem device employing nanoscale interface engineering of Cu(In,Ga)Se2 surface alongside a heavy-doped poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] hole transporting layer between the two subcells that preserves open-circuit voltage, and enhanced both fill factor and short-circuit current. As a result, we have successfully doubled the previous efficiency record for a monolithic perovskite/Cu(In,Ga)Se2 tandem solar cell to 22.43% power conversion efficiency, which is the highest record among thin film monolithic tandem photovoltaic devices. The conclusion and future outlooks of my works on kesterite and perovskites solar cells are summarized in Chapter 6.
Nanoscale Measurements of the Surface Photovoltage in Cu(In, Ga)Se2, Cu2ZnSn4, and Cu2ZnSnSe4 Thin Films
Author: Publisher:
ISBN:
Category : Photovoltaic power generation
Languages : en
Pages : 4
Book Description
We report on recent advances in the development of nanoscale measurements of the surface photovoltage (SPV) based on scanning tunneling microscopy (STM) and its application to the kesterites Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe). One critical aspect of the electronic structure of Cu(In, Ga)Se2 (CIGS) that has yet to be determined in their related kesterite compounds is the character of the surface electronics. In CIGS, spontaneous deviations in the stoichiometry of the surface cause a depletion (or even a type inversion) region that reinforces the CIGS homojunction. First-principle calculations predict that this inversion region will be more difficult to form in CZTS. In this contribution, the characteristics of the surface space charge region for both CIGS and CZTS(e) are investigated by STM. The implications of the results of these measurements on the future development of CZTS solar cells will be discussed.
The Role of the Heterointerfaces in the Cu(In, Ga)Se2 Thin Film Solar Cell with Chemical Bath Deposited Buffer Layers
Author: Hong-Quang NguyenX-ray Nanoprobe and Electron Beam Investigations of Kesterite and Chalcogenide Thin Film Solar Cells
Author: Maurizio RitzerPublisher:
ISBN:
Category :
Languages : de
Pages :
Book Description
As an alternative for Si-based solar cells Cu2ZnSn(S,Se)4 (CZTSSe) and Cu(In,Ga)Se2 (CIGS) thin film solar cells have recently received great attention as their efficiency has been steadily increased over the past decades. Nevertheless, the efficiency is still below the theoretically predicted upper limit, which is mainly related to inhomogeneities in the absorber composition, structural defects, and the formation of secondary phases. This thesis provides insights into efficiency-limiting properties of highly efficient Ge-doped CZTSe, CZTSSe, and CIGS thin film solar cells by accessing local compositional, structural, microstructural, and functional properties using a combinatorial approach of electron- and advanced synchrotron-based methods at the nanoscale: First, it has been demonstrated that an exceptionally homogeneous element distribution in the CZTSe absorber accompanied by the absence of harmful Cu-, Zn- or Sn-based secondary phases is achieved by introducing small amounts of Ge during the synthesis. Within the absorber, Ge is heterogeneously incorporated into the CZTSe matrix, but also forms nanoscale GeO2 secondary phases. Second, the interplay of performance-limiting nanoscale features in CZTSSe solar cells were revealed. Investigations of the local composition indicates the formation of harmful ZnS(Se) secondary phases whose presence, number, and dimension increases strongly with the reduction of Cu and the increase of Zn content. Furthermore, the local composition of the CZTSSe phase shows strong variations within the absorber, which significantly reduces the efficiency. Third, a CIGS solar cell that underwent a post-deposition treatment with RbF was investigated in a combinatorial approach, which simultaneously monitors the local composition and device functionality. This work demonstrates that Rb-enriched grain boundaries have a negligible influence on the collection efficiency, indicating the passivation of detrimental defects.
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