AVS 58th Annual International Symposium and Exhibition
    Energy Frontiers Focus Topic Wednesday Sessions
       Session EN+EM+NS-WeM

Paper EN+EM+NS-WeM6
Selective and Highly Efficient Photo-Induced Activity Over Nano-Scale Sites in Porous Silicon: Potential Application for Hybrid Organic-Silicon PV

Wednesday, November 2, 2011, 9:40 am, Room 103

Session: Quantum Dot and Nanowire Solar Cells
Presenter: Micha Asscher, The Hebrew University of Jerusalem, Israel
Authors: M. Asscher, The Hebrew University of Jerusalem, Israel
G. Toker, Hebrew University, Israel
A. Nahor, Hebrew University, Israel
O. Berger, Hebrew University, Israel
S. Yitzchaik, Hebrew University, Israel
A. Sa'ar, Hebrew University, Israel
Correspondent: Click to Email
Photo-induced processes over solid surfaces are of great basic and technological interest with applications in e.g. photolithography, sensing, catalysis and photovoltaics. Photo activity within porous silicon (PSi) following UV (193-266nm) irradiation has been studied. Unusually efficient, non-thermal, morphology and wavelength dependent photo-induced desorption (PID) of Xe was recorded. It is a selective process, revealing more than 3 orders of magnitude enhancement within pores, at the vicinity of nano-scale silicon tips, over atoms adsorbed on top of flat surfaces. Remarkably large cross sections up to σPSi= 2∙10-15cm2 were recorded, significantly larger than any previously published photo-induced events on solid surfaces at this wavelength range. Long lived, photo-induced positive charges (holes) located at inner surface nano-tips is proposed to stabilize transient negative Xe adsorbate ions as the precursor for this new photo-desorption process.

These results were utilized for the construction of hybrid conducting polymer-porous silicon photovoltaic cell. Proof of concept and preliminary results are discussed.