login

Search documents

Browse topics

Document details

 
Title:
 
Photocurrent in the Sub Bandgap Region of a-Si:H Photosensitive Devices Induced by Ag Nanoparticles
 
Author(s):
 
F. L√ľkermann, U. Heinzmann, H. Stiebig
 
Keywords:
 
Hydrogenated Amorphous Silicon, Silver Nanoparticles (Ag-NPs), Localized Surface Plasmon Resonance, Sub Bandgap Photocurrent, Impurity Photovoltaic Effect
 
Topic:
 
Material Studies, New Concepts and Ultra-High Efficiency
Subtopic: New Materials, Cells and Modules
Event: 27th European Photovoltaic Solar Energy Conference and Exhibition
Session: 1BV.8.7
 
Pages:
 
367 - 370
ISBN: 3-936338-28-0
Paper DOI: 10.4229/27thEUPVSEC2012-1BV.8.7
 
Price:
 
 
0,00 EUR
 
Document(s): paper
 

Abstract/Summary:


In this contribution the absorption by defect states in hydrogenated amorphous silicon (a-Si:H) photosensitive devices in the environment of resonant absorbing silver nanoparticles (Ag NPs) is investigated. The location of defects in the strong electromagnetic fields accompanied by the localized surface plasmon (LSP) resonance of the Ag NPs enable high transition rates between the defect states and the conduction band. This results in a significant signal for near infrared (NIR) photon energies in external quantum efficiency (EQE) measurements. Dominant transitions take place for defect levels with an energetic distance from the conduction band, equal to the LSP resonance energy. Introducing a boron doped layer in direct contact to the NPs leads to a decrease of the NIR EQE signal. This gives evidence for the existence of the NP induced defect states in the a-Si:H material. The p-type doping shifts the Fermi level towards or below the defect states resulting in their depletion. Therefore these states cannot contribute to sub bandgap photon absorption resulting in a decreased NIR EQE signal.