Contact: Dr Christophe Couteau
-Laboratory for Nanotechnology and Optical Instrumentation (LNIO)
-Troyes University of Technology (Troyes)
-PhD project title: Nanowire-based photodetector with high gain (NanoGain)
The goal of the project NanoGain is to study the photoconductive gain of semiconductor nanowires. Recently, such nanostructures have come across as being very good photodetectors with an important gain (current/light conversion) and could be as efficient as the state of the art commercial detectors. Nevertheless, the true measurement of this photoconductive gain remains unknown and the purpose of NanoGain is to address 2 issues: 1) to use a single photon source for accessing the intrinsic gain of a single semiconductor nanowire and 2) to channel the light efficiently towards the nanowire for efficient detection. We thus propose to send a controlled number of photons (using a single photon source) onto a single nanowire. In order to make sure the nanowire absorbs the light efficiently, we will couple together the photon source and the nanowire detector with a plasmonic guide which will funnel the light from the source to the detector.
The methods used in this project will be: setting-up a microphotoluminescence experiment at room and low temperatures, growing various III-V semiconductor nanowires with different doping concentrations and dimensions, contacting and fabricating metallic slots for the plasmonic waveguide and finally measure the gain upon illumination with a faint laser source and a single photon source.
The results and perspectives for this project are a better knowledge of light-matter interaction at nanometer scales as well as a better understanding of the physical phenomena responsible for the high internal photoconductive gain in semiconductor nanowires.
This project is mostly experimental although some simulation will be done too.
-Dates: Start in September 2011 for 3 years.
-Funding: secured from the Champagne-Ardennes region council for 3 years. The selection of the candidate will be very severe.
-Preferred skills: quantum optics, integrated optics, semiconductor optics
-Project in collaboration with Prof C. Soci from NTU Singapore and UMI CINTRA for the nanowire growth.
-Contact : Please send CV and motivation letter to Dr Christophe Couteau, couteau@utt.fr