INSTITUTE OF PHYSICS PUBLISHING JOURNAL OF PHYSICS: CONDENSED MATTER J. Phys.: Condens. Matter 16 (2004) 7557–7564 PII: S0953-8984(04)77414-7 Erbia-modified electrospun titania nanofibres for selective infrared emitters R Teye-Mensah 1 , V Tomer 1 , W Kataphinan 2 , J C Tokash 1 , N Stojilovic 1,3 , G G Chase 4 , E A Evans 4 , R D Ramsier 1,3,4 , D J Smith 3 and D H Reneker 2 1 Department of Physics, The University of Akron, Akron, OH 44325, USA 2 Maurice Morton Institute of Polymer Science, The University of Akron, Akron, OH 44325, USA 3 Department of Chemistry, The University of Akron, Akron, OH 44325, USA 4 Department of Chemical Engineering, The University of Akron, Akron, OH 44325, USA E-mail: rex@uakron.edu Received 3 March 2004, in final form 8 September 2004 Published 1 October 2004 Online at stacks.iop.org/JPhysCM/16/7557 doi:10.1088/0953-8984/16/41/032 Abstract Tetraisopropyl titanate (TPT) was mixed with a solution of polyvinylpyrroli- done (PVP) and the solution electrospun into nanofibres. Thermal annealing at 900 ◦ C was used to pyrolyse the PVP, leaving nanofibres of rutile-phase titania. Erbium (III) oxide particles were also added into the solution before electrospin- ning, and selectively modified the near-infrared optical properties of the titania nanofibres as verified by both absorption and emission spectra. We thereby demonstrate the production of high-temperature optically functionalized nanos- tructures that can be used in a thermophotovoltaic energy conversion system. 1. Introduction Electrospun nanofibres have potential for use as biomaterials, sensors, photovoltaic cells, filtration media, and mechanical supports for other materials [1]. Surface modifications of electrospun nanofibres have been demonstrated [2–6], and the incorporation of particles within electrospun nanofibres has also been reported [7, 8]. Recently the electrospinning process has been used to make hybrid polymer, ceramic, and metal oxide nanofibres and tubes [9–15]. The emphasis here is on the production of titania nanofibres with selectively modified optical properties for use in energy conversion and utilization systems. One of these potential applications, thermophotovoltaics (TPV), is a promising energy conversion technology for the direct production of electricity from the infrared (IR) light radiated by a hot emitter [16–25]. The salient features of an idealized TPV system are a source of thermal energy, an emitter, and an IR photovoltaic cell which serves as the collector. The origin of the thermal energy is unrestricted, and can range from industrial waste streams 0953-8984/04/417557+08$30.00 © 2004 IOP Publishing Ltd Printed in the UK 7557