Laser processing of TiO2 films for dye solar cells: a thermal, sintering, throughput and embodied energy investigation

• Published in: Progress in photovoltaics Vol. 22; no. 3; pp. 308 - 317
• Main Authors: Mincuzzi, G., Schulz-Ruhtenberg, M., Vesce, L., Reale, A., Di Carlo, A., Gillner, A., Brown, T. M.
• Format: Journal Article
• Language: English
• Published: Bognor Regis Blackwell Publishing Ltd 01.03.2014; Wiley; Wiley Subscription Services, Inc
• Subjects: Applied sciences; dye solar cell fabrication; Efficiency; Energy; Exact sciences and technology; laser sintering; Lasers; Natural energy; Photovoltaic conversion; scanning laser processing; Solar cells. Photoelectrochemical cells; Solar energy; TiO2 films; Performance evaluation; Dye-sensitized solar cell; films; Output power; Conversion rate; Ultraviolet laser; Laser assisted processing; Active layer; laser sintering; Optimization; Automatic processing; dye solar cell fabrication; Laser beam; Pulsed laser; Sintering; Energy conversion; Thermal imaging; Open market; TiO; Titanium oxide; Nanocrystal; Thermography; scanning laser processing
• ISSN: 1062-7995; 1099-159X
• DOI: 10.1002/pip.2261

ABSTRACT We have analysed and optimised a laser process for the sintering of the TiO2 layers in dye solar cells (DSCs). Through a thermographic characterisation of the process, we show that it is possible to scale and process large areas uniformly (16 cm2). We fabricated DSCs with nanocrystalline (nc)‐TiO2 films sintered by using pulsed ultraviolet laser with an average output power P varying from 1 W to 7 W whilst mainting a constant power conversion efficiency η. The highest efficiency reached for a laser sintered DSC was 7%. The time required to sinter 1 m2 of nc‐TiO2 film was found to decrease hyperbolically with P, which is important for determining process takt times. We quantified the embodied energy (EE) required to sinter 1 m2 of the active TiO2 layer for a variety of different processes, and found that the EE for the laser sintering process with a system wall plug efficiency of 3.5% to be competitive with the more conventional oven and belt furnace treatments. We outline the main features required from a laser system to carry out an efficient, energetically favourable and industrially applicable automated process with competitive throughput. Copyright © 2012 John Wiley & Sons, Ltd. We have analysed and optimised laser sintering of nc‐TiO2 layers for dye solar cells (best cell efficiency 7%) showing that large areas can be processed uniformly. The time required to sinter 1m2 of nc‐TiO2 was found to decrease hyperbolically with laser output power. The embodied energy of the sintering process via efficient lasers was found to be competitive with conventional oven/furnaces. We outline the features required from a laser system to carry out an industrially applicable process with competitive throughput.