High-speed atmospheric atomic layer deposition of ultra thin amorphous TiO2 blocking layers at 100 °C for inverted bulk heterojunction solar cells

• Published in: Progress in photovoltaics 2013-06, Vol.21 (4), p.393-400
• Main Authors: Muñoz-Rojas, David, Sun, Haiyan, Iza, Diana C., Weickert, Jonas, Chen, Li, Wang, Haiyan, Schmidt-Mende, Lukas, MacManus-Driscoll, Judith L.
• Format: Article
• Language: English
• Subjects: Applied sciences; blocking/selective/barrier layers; bulk heterojunction polymer solar cells; compatible with roll-to-roll processing; Energy; Exact sciences and technology; Natural energy; Photovoltaic conversion; printing of oxides; Solar cells. Photoelectrochemical cells; Solar energy; spatial atmospheric atomic layer deposition (ALD); thin film deposition
• ISSN: 1062-7995; 1099-159X
• DOI: 10.1002/pip.2380

ABSTRACT Ultrafast, spatial atmospheric atomic layer deposition, which does not involve vacuum steps and is compatible with roll‐to‐roll processing, is used to grow high quality TiO2 blocking layers for organic solar cells. Dense, uniform thin TiO2 films are grown at temperatures as low as 100 °C in only 37 s (~20 nm/min growth rate). Incorporation of these films in P3HT‐PCBM‐based solar cells shows performances comparable with cells made using TiO2 films deposited with much longer processing times and/or higher temperatures. Copyright © 2013 John Wiley & Sons, Ltd. The potential of a novel spatial atmospheric atomic layer deposition (AALD) system for the ultrafast, low temperature fabrication of high quality blocking layers is demonstrated. Thin (~12 nm) amorphous TiO2 films can be deposited at 100 °C in only 37 s over a 7.8 cm2 area. P3HT‐PCBM‐based solar cells fabricated with the AALD films show performances comparable with cells made using TiO2 films deposited with orders of magnitude longer processing times and/or higher temperatures. In addition, the novel AALD system is easily scalable and compatible with roll‐to‐roll processing.