A ray tracing investigation of light trapping due to grooves in solar cells

The biggest problem the world faces today is finding a renewable energy source as fossil fuel reserves being depleted, and the ongoing burning of fossil fuels is destroying environments all over the world. Solar energy is the most abundant energy source but is too expensive compete with non-renewable sources. A way to increase the efficiency of solar cells is to texture the cell surface so that it traps light better, allowing more light to be absorbed and converted to electrical energy. Professor Sachs and Dr. James Bredt have developed a texturing scheme that consists of trenches etched on the top surface of the silicon cell. The profile of the trenches will either be a simple semicircle or a parabola with a set aspect ratio. Our objective was to determine the optimal cross-sectional shape by using Zemax, a ray-tracing program that models light striking the cell. Solid Models of the solar cell with different texturing schemes were created, and then imported to Zemax where optical properties were modeled. Using a detector to measure how many times a ray struck the bottom surface of the cell, we were able to determine that a parabola with a unit aspect ratio was the optimal trench cross-section. The average number of detector hits for the unit aspect parabola was 3.68 ± 0.11 as oppose to 1 detector hit with no texture.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Ruggiero, Christopher W

Advisor dc:contributor.advisor

• Emanuel M. Sachs.

• Mechanical 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/1721.1/40469

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/40469