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ECGR 3090 solar cell fabrication

7 Novemeber 2014Name

This report was submitted in compliance with the UNCC Code of Student AcademicIntegrity (2003-05 UNCC Catalog, p 276) AB OP

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ECGR 3090 Solar Cells - Summary

A solar cell uses the photovoltaic effect to convert sun light into usable electricity.

The goal in this class was to fabricate a silicon solar cell in the Cameron clean room using existing equipment and processes.

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Diagram of Solar Cell

As fabricated the Cameron clean room

(Al)

(Al)

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Clean Room Safety

A safety test must be completed and passed before entering the clean room.

Chemical gloves are worn when handling any chemical.

Chemicals are disposed of properly and in the correct containers.

Material Safety Data Sheets are placed in each room with harmful chemicals.

Safety shower and eye wash are placed in case of a chemical spill on a person.

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Contamination Mitigation

Different tweezers are placed in each station.

Special garments are worn at all times while inside the clean room.

Clean room is kept filtered to keep as much dust out as possible.

Sticky floor mats are placed at all entrances to the clean room to get dirt off of shoes.

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Traveler

Fabrication Photos

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4 Point Probe

Chemical Cleaning

PECVD – Backside SiO2

Fabrication Photos

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4 Point Probe

Photolithography

Front Side Conductor Deposition

Diffusion in Furnace

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Photo Mask Used

Fabrication Photos

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Annealing Furnace – 450C

Wafer Dicing

Sputtering Tool – Backside Deposition

PECVD - Antireflective SiO2

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Solar Cell TestingCell placed on test plate with probe on center bus

Cell is illuminated by the test lamp – Original test was done at 0.93 sunSecond test was done at .88 sunAir mass filter was 1.5 for both tests

Test results appear as an IV plot on the computer

Small cell in testing

Large cell in testing

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Cell Results

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Cell Results

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Results

Large CellVoc 0.6 VIsc 140 mA

Vmp 0.25 VImp 75 mA

Max current 150 mASize 6.0588 cm^2

Fill factor 0.223Jsc 23.107 mA/cm^2

Efficiency 3.33%

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Conclusion

One wafer was broken while being removed from the furnace.

One wafer exhibited signs of a leaky diode – possibly from spinning dopant multiple times due to dust appearing on wafer.

One wafer tested normal.