The controlled wetting of porous silicon surfaces by self-assembly of organosilanes is one of the main objectives of the project “ESR04: Humidity effects at the organic/porous silicon sensor interface”. Organosilane-modified porous silicon prepared at UAM has been characterized by focused ion beam tomography and scanning electron microscopy at CIC nanoGUNE. The tomographic analysis has allowed to individualize permeable and impermeable structures as a function of organosilane end group. The use of contrast agents has permitted to image dendritic pore growth. These results are relevant from the point of view of volumetric vs surface functionalization of porous silicon-based sensors.
Image: FIB tomography of porous silicon stained with phosphotungstic acid. The pores are filled with the stain; each pore is colored separately. The dark green system is 4 micron in height and 0.750 micron wide.
Movie: FIB tomography slice of ca. 10x4x4 micron
Collaborators in this project are: Chloe Rodriguez and Miguel Manso, UAM, Madrid Alexander M. Bittner and Andrey Chuvilin, CIC nanoGUNE, Donostia-San Sebastian Evgenii Modin, National Research Centre “Kurchatov Institute”, Kurchatov Sq. 1, Moscow, Russia