Solar cells based on InGaN nanostructures

Completed

Renewable Energy Sources(Solar Energy, Photovoltaics)

Basic and strategic applied research

PHYSICAL SCIENCES AND MATHEMATICS (Chemistry)
PHYSICAL SCIENCES AND MATHEMATICS (Physics)

Not Cross-cutting

Professor D Cherns
Physics
University of Bristol

Standard

EPSRC

01 October 2011

30 September 2014

36 months

£429,592

Info. & commun. Technol.

South West

Photonic Materials and Devices

Professor D Cherns, Physics, University of Bristol

Dr RP Campion, Physics and Astronomy, University of Nottingham
Dr DJ Fermin, Chemistry, University of Bristol
Professor CT Foxon, Physics and Astronomy, University of Nottingham
Professor A Kent, Physics and Astronomy, University of Nottingham
Dr CJ Mellor, Physics and Astronomy, University of Nottingham
Dr S Novikov, Physics and Astronomy, University of Nottingham

Project Contact, Arizona State University, USA

There is a worldwide effort to increase power generation through solar cells, to meet targets in reducing greenhouse gases. One requirement is for high efficiency multijunction solar cells (MJSCs) to extract power from concentrated solar power (CSP) plants, which are expected to become central to the delivery of solar power to national and super-grid systems. At present such MJSCs must combine different materials systems, and are usually limited by the requirement to lattice-match the individual cells to avoid efficiency losses due to defects. In this proposal we aim to circumvent these problems by investigating solar cells based on InxGa1-xN, which has a direct band gap of 0.7-3.4 eV, spanning most of the visible spectrum, thus promising MJSCs from a single materials system. To avoid the problems of lattice mismatch and of material quality, which limit prototype solar cells based on InxGa1-xN epilayers to low x (x<0.3), we will grow the InxGa1-xN in nanorod form, merging the nanorods using methods we have already developed to provide a solar cell template. The team assembled, which combines complementary expertise in growth and device fabrication (U. Nottingham), structural characterization (U. Bristol), nanoscale optical and electrical characterization (Arizona State U.) and solar cell design and characterization (NREL), aims to explore the properties of InxGa1-xN single junction cells over the full composition range (0‹x‹1). The team will examine key fundamental properties of InxGa1-xN nanorods, using transmission and scanning electron microscopy to determine the materials requirements for growing defect-free InxGa1-xN nanorod arrays, and overcoming the problem of lattice mismatch. The work will examine the electronic properties of InxGa1-xN nanorods using novel cathodoluminescence and electron holography studies, and time-resolved photoluminescence. Single junction solar cells will be fabricated and characterized for InxGa1-xN nanorods with low and high In content, and exploratory work will be carried out into a novel two-junction nanorod cell including a tunnel junction, thus establishing the requirements for the future development of InxGa1-xN MJSC devices

02/12/11