Title:	Oxide nanowires for solar cell applications and Polymer-based thermoelectric materials
DNr:	SNIC 2018/3-515
Project Type:	SNIC Medium Compute
Principal Investigator:	Alberto Vomiero <alberto.vomiero@ltu.se>
Affiliation:	Luleå tekniska universitet
Duration:	2018-11-01 – 2019-11-01
Classification:	10304
Keywords:

Abstract

We want to use density functional theory simulations for the exploitation of new materials in technology to complement our present experimental efforts. We therefore request resources for two separate projects. (1) Oxide nanowires for solar cell applications The main purpose of this project is to investigate coaxial oxide nanowires for the development of stable, highly efficient and scalable solar cells. Nanostructures are interesting options to be used in photovoltaics since more surfaces and interfaces may lead to an increased ability for light to excite electrons to produce electricity. It is well known that properties of traditional crystalline solids changes as the size of the crystal approaches the nanoscale. The energy bands become less dispersive and becomes more similar to the specific energy levels of molecules. It is therefore not necessarily traditional solar cell materials that are the best options to be used in nanostructured solar cells. Instead we will search for non-traditional and cheap materials to be used instead.[1,2] In this project we will model different oxides as nanomaterials, e.g. as oxide nanowires, to tailor their light absorption efficiency along with their conduction properties. These oxide nanowires will lead to alternative solutions within photovoltaics and could be of large importance for the solution of our present energy and environmental challenges. [1]. P. F. Navarro Prado, D. Benetti, V. Benavides, H. Zhao, S. G. Cloutier, V. M. Castaño, A. Vomiero, F. Rosei, J. Solid State Sci. Tech. 6 (2017) 32. [2]. I. Concina, A. Vomiero, Small, 11 (2015) 1744. (2) Polymer-based thermoelectric materials The importance of energy cannot be overestimated in our world today. Apart from looking for new energy sources, research groups all over the world are working on the improvement in the field of energy utilization. Thermoelectric energy conversion, where waste heat is transformed into useful electricity, can greatly increase our energy efficiency by making energy resources last longer and not being wasted as heat. Here we will focus on polymer-based thermoelectric materials.[3,4] In order to have a high efficiency in the thermoelectric energy conversion, the so-called power factor needs to be high. Unfortunately, the power factor is low for polymers. However, it is possibly to raise the power factor through filler intercalation, doping and chemical treatment, and post-treatment. Here we will study the influence of AuCl4 alcohol solution on the thermoelectric properties of aerosol synthesized single-walled carbon nanotubes (AE-SWCNTs) as fillers in a poly(3,4-ethylene dioxythiophene) polystyrene sulfonate (PEDOT: PSS) matrix. In addition, the influence of Au and AuCl4 doping on the thermoelectric properties of single-walled carbon nanotubes will be investigated. [3] K. Yusopov, S. Stumpf, S. You, A: Bogach, P. M. Martinez, A. Zakhidov, U. S. Schuvert, V. Khovaylo, A: Vomiero, Adv. Funct. Mater. 2018 DOI: 10.1002/adfm.201801246 [4] K. Yusupov, A. Zakhidov, S. You, S. Stumpf, P. M. Martinez, A: Ishteev, A. Vomiero, V. Khovaylo, U. Schubert, J. Alloys and Comp. 741 (2018) 392-397.