NIR silicon photodetector enhancement using photonic crystal cavity resonators

The growing demand for efficient infrared sensors for light ranging, thermal-cameras, and soon, free-space optical communications has yet to be answered. In this study, we use polycrystalline silicon in conjunction with a photonic crystal cavity (PhCC) to enhance light absorption for efficient sensing. We present a cost-effective alternative to the current III-V detectors. By adding a 2D-PhC resonator layer, surface-illuminated light can be confined within a 10 micron region with great intensity, leading to a higher effective path-length and improved detector responsivity. More than 1000 variants of this detector are designed and implemented in a 65nm CMOS process. Using a nearest neighbor method, we find the optimized designs. We validate experimental findings by simulating mode behavior of the PhCC structures using FDTD models. In addition, a numerical study on cavity parameter optimization for achieving high Q-factors and extinction ratios specifically for surface-illumination is presented. We report polysilicon PhCC-enhanced sensors with Q-factors of 6500 resulting in responsivities at 1300nm up to 0.13mA/W -a 25x improvement over non-resonant surface-illuminated Silicon detectors.

Name thesis:degree_name

Bachelor

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Physics

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2019

Author dc:creator

• Al Johani, Ebrahim Dakhil.

Advisor dc:contributor.advisor

• Rajeev J. Ram and Marin Soljačić.

• Physics.

Statement dc:rights

• MIT theses may be protected by copyright. Please reuse MIT thesis content according to the MIT Libraries Permissions Policy, which is available through the URL provided.

Licence dc:rights.uri

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

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/128418

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/128418