Study on the photoelectric hot electrons generation and transport with metallic-semiconductor photonic crystals

Photoelectric hot carrier generation in metal-semiconductor junctions allows for optical-to- electrical energy conversion at photon energies below the bandgap of the semiconductor. Which opens new opportunities in optical sensors and energy conversion devices. In this thesis research, the wafer-scale metallic-semiconductor photonic crystal (MSPhC) has been designed for photoelectric hot electrons collection. The periodic nano-cavities structure of MSPhC supports various optical modes that can resonate with light in broad wavelength region. Optical simulation and experimental results of MSPhC have been demonstrated. The simulation results shows MSPhC can achieve up to 70% absorption in the solar radiation range, with ultra-thin metal film. Experimentally, MSPhC has fabricated via 6" Si wafer scalable microfabrication techniques. A broadband sub-bandgap hot electron response with a full width at half maximum (FWHM) of 235 nm centered at 590 nm is observed. Photoresponse enhancement factor of 12.28 at 639 nm compared to a flat chip is also measured. Applications of these results could lead to low-cost and robust photoelectrochemical device such as full-spectrum solar water splitting.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Materials Science and Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2015

Author dc:creator

• Wang, Yu

Advisor dc:contributor.advisor

• Sang Gook Kim.

• Materials Science and Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/98730

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/98730