Light Management in Solar Cells using Fault-Tolerant Plasmonics and Metamaterials [MetaSol]

The proposed project (MetaSol) aims to develop cheap and fault-tolerant Schottky plasmonic-based solar cells. It is of an interdisciplinary nature where a team with diverse skill sets will work in synergy towards that aim. The main needed skill sets are optical engineering, metamaterials, materials growth and synthesis, and device physics. As known, the cost of solar cells (in term of $/W) is still more expensive than many other energy resource alternatives. Industrial-wise and due to the multilayer nature of the conventional solar cell technologies, fabrication cost beside the reduced efficiency and industrial yield are the main factors elevating the total cost. Recently, solar cell technologies have advanced in several fronts. Most of the stagnated methodologies were considerably enhanced. These developments are mostly based on improved material growth quality and fabrication sophistication. However, this obviously resulted in an increased fabrication cost and it would need extensive industrial research to make them commercially lucrative. We propose here an alternative way where the focus is on reducing the fabrication cost while maintaining a decent efficiency such that the overall $/W cost is reduced. There are two main essential components of this work. The first is to utilize fault-tolerant plasmonics and metamaterials to manage the light in the cell; i.e. to considerably reduce the required absorption length as discussed in detail later. Certainly, adopting plasmonics in solar cell is not new where there have been deployed for organic photovoltaics and some inorganic solar technologies as well. However, they were only used utterly for light management (in many cases, this resulted in further device sophistication). In this work, we add to light management using the plasmonics another role to extract the photo-generated carriers as they are mostly need metals. This leads to the second component of the proposed work, which is to adopt the Schottky structure for the cell rather than the conventional p-n junction configuration. As shown in previous work (discussed in Section 2), Schottky plasmonic-based solar cells has remarkably a simple structure. Simply, the absorber is sandwiched between two metallic gratings. By appropriate design, we can ensure that the majority of incident radiation is absorbed by the absorber with little losses due to reflection and light absorbance by the metals. MetaSol will follow a bottom-up methodology, i.e. by going from the basic theoretical understanding of the fundamentals of the new elements (such as plasmonic and metamaterial elements) and multi-physics approach needed for MetaSol long-term vision. This will permit the design and characterization of the basic building blocks and, finally, the integration of the new photovoltaic device and its validation as a proof-of-concept of a plasmonic bifacial Schottky solar cell with unprecedented capabilities. The theoretical study, design and modelling will require several theoretical methods to calculate the fundamental properties of the basic building blocks to be developed in the project and to ensure to a satisfactory consideration of multi-physics coupling. In particular, the development of plasmonic/optical interaction and the design of the GUI-interface will be carried out using commercial software (COMSOL MULTIPHYSICS and MATLAB). The work will be local and conducted totally in QEERI, HBKU. As discussed later in detail, the work is organized into 4 work packages (WP). WP-1 is dedicated to the plasmon-enhanced theoretical understanding of the photovoltaic properties of the solar cell (SC) in its globality (i.e. by incorporating optical, electrical, and thermal effects). WP-2 is dedicated to the development and optimization at the device level with the newly established concepts (e.g. bifacial operation of the SC). WP-3 concerns the experimental realization of the proof-of-concept devices. WP-4 is intended for the management, communication, dissemination and exploitation activities. The main scientific objective of the current proposal is the development of fundamental scientific and technological knowledge and personal skills in the emerging field of optical metamaterials and plasmonic metasurfaces for photovoltaic (PV) applications. This consists of the design, the fabrication, and the characterization of a prototype of Schottky plasmonic-based solar cells (monofacial and bifacial) with efficiencies that go beyond the state-of-the-art (SOTA) while maintaining the ease of fabrication, and the use of current technology. To this purpose, we sought to take advantage of the particular optical properties and tunable plasmonic and/or photonic structures, characterized by spatial periodicity of the dielectric tensor. We propose to bring the concept of Schottky PV devices ‎one-step closer to its practical applications by enhancing the yield (power conversion efficiency) using some of the most promising concepts. More explicitly, we propose to take advantage of photonic engineering concepts to increase the absorption in SC from silicon industry or using other active materials. Concepts, such as the bifacial Schottky SC will also be considered and further fabricated and their robustness and fault-tolerance will be investigated in-depth in the framework of this proposal. All these effects have never been studied before, to the best of our knowledge

Hamad Bin Khalifa University (HBKU)