Opt Quant Electron (2018) 50:237 https://doi.org/10.1007/s11082-018-1507-z 1 3 Metal layers with subwavelength texturing for broadband enhancement of photocatalytic processes in microreactors M. Rašljić 1  · M. Obradov 1  · Ž. Lazić 1  · D. Vasiljević Radović 1  · Ž. Čupić 2  · D. Stanisavljev 3 Received: 26 October 2017 / Accepted: 18 May 2018 © Springer Science+Business Media, LLC, part of Springer Nature 2018 Abstract In this paper we joined plasmonics and microreactors for photocatalytic opto- fuidic devices. To this purpose we consider the use of subwavelength texturing of plas- monic flms applied to microreactor channel bottom to ensure SPP localization and feld enhancement. The small volume of the microchannel is ideal for the enhancement of pho- tocatalytic processes using localized evanescent felds. A great advantage of our approach is that it is highly compatible with the standard chemical bulk micromachining techniques which are commonly used in fabrication of the microreactors i.e. standard photolithogra- phy can be used to defne microchannels, and radiofrequent sputtering to deposit a gold flm as a plasmonic material over the roughened surface. Subwavelength surface texturing can be obtained by varying etching techniques and parameters and the microreactor build- ing materials. We show using ab initio FEM modeling that the stochastic surface profle ensures broadband coupling of visible light as well as enables us to merge plasmonic sen- sors and microreactors into a single device. Keywords Plasmonic · Microreactors · Thin flms · Photocatalysis This article is part of the Topical Collection on Focus on Optics and Bio-photonics, Photonica 2017. Guest Edited by Jelena Radovanovic, Aleksandar Krmpot, Marina Lekic, Trevor Benson, Mauro Pereira, Marian Marciniak. * M. Rašljić milena@nanosys.ihtm.bg.ac.rs 1 Centre of Microelectronic Technologies, Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoševa 12, 11000 Belgrade, Serbia 2 Centre of Catalysis and Chemical Engineering, Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoševa 12, 11000 Belgrade, Serbia 3 Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, 11000 Belgrade, Serbia