Functionalization of conducting oxides by ion beam and defect engineering (FUNCTION)

The goal of the FUNCTION project is to develop novel oxide-based functionality compatible with the prevailing silicon technology for Photovoltaics (PV) devices by understanding and manipulating the electro-optical interaction between embedded semiconducting nanocrystals and a conductive oxide host material.

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About the Project

A paramount challenge facing our common global future is access to sufficient supply of clean energy. Global energy demand is expected to double by year 2050 and electricity demands are expected to triple. To meet these growing electricity demands, solar energy conversion using PV is an outstanding alternative and a large scale industrial sector almost exlusively based on silicon-technology has emerged. However, the performance of Si solar cells is fundamentally limited by their conversion efficiency. Hence, disruptive innovations are required for further penetration of fossil-free energy production, but also for storage, conversion and distribution.

Different concepts have been suggested to overcome the Shockley-Queisser limit for conversion efficiency. The suggestions include implementation of high cost tandem cells, introduction of impurity band and intermediate band devices, hot electron extraction, and carrier multiplication (CM). An intriguing approach is to join one or more of these new concepts with the prevailing silicon technology. Today, there is a trend in PVs towards replacing the Si-nitride-based antireflective coating with a transparent conductive oxide (TCO) layer. The purpose of this substitution is to enhance charge collection and reduce shadowing effects from contact metal fingers. However, the TCO can also be functionalized with oxide semiconductor nanoparticles, which would give the TCO an active role in solar energy extraction.

FUNCTION aims to increase efficiency and lower costs of PVs through the use of abundant and environmentally friendly materials. The proposed route to these goals is the functionalization of TCOs through embedding of semiconducting nanoparticles. The functionalized TCO can then be integrated in a larger heterostructure device, building on existing Si-based technology. In addition, TCOs functionalized with semiconducting nanoparticles have recently seen interest for use in detectors, so the possible applications of the technology also go beyond photovoltaics.

The contributors to Function aim to use electron microscopy (SEM and TEM), luminescence (photoluminescence and cathodoluminescence) as well as XPS and scattering techniques to characterize the fabricated nanocomposites. Different fabrication pathways are under consideration but the current focus is on nanoparticle growth during heat-treatments following ion implantation.

The Project is led by UiO and will run for 3 years.

Financing

The Research Council of Norway.

Tags: Photovoltaics, Transparent conducting oxides, Semiconductor physics, Nanotechnology
Published Sep. 16, 2020 12:39 PM - Last modified Dec. 28, 2020 5:19 PM