20.109(F11): Mod 3 Day 5 Solar cell testing

Solar Cell Testing

Introduction

Over the first four lab sessions of this module, you have completed the anode portion of a dye-sensitized solar cell, which means that your device currently has the ability to absorb light with dye molecules and use that energy to inject electrons through a single-walled carbon nanotube (SWNT) shuttle into the start of an external circuit. However, in order for this to create electrical power, you must complete the external circuit with a counter-electrode and you must have a redox mediator that accepts electrons from this counter-electrode and recycles them back to the dye molecules. The image below represents the fully completed dye-sensitized solar cell that you'll have built by the end of today.

Once completed, you will get to test one of the most important comparative factors for all existing solar technologies, the "solar conversion efficiency"; this is a measure of the total amount of electrical power produced for a given amount of solar power shining upon the cell. It should be remembered though that many other factors of solar technologies, such as ease and cost of manufacturing, durability, and cost of materials are imperative to consider when contrasting different types of solar cells and could make impractical even those that are the most conversion efficient.

Protocols

Part 1: Completion of Assembly

1. Using a pair of forceps, remove the piece of glass that contains your solar device from the dye solution.
2. Rinse off the dye solution using the following series of washes: Let the anode-base dry completely. (The device should look like the photo on the right)
3. Next, the anode needs to be coated in a layer of Surlyn (a trademarked resin from Dupont) to assure that when it is later connected to the counter electrode that the electrolyte solution that completes the solar cell will be sealed completely between the two. The Surlyn comes as a bi-layered product with one layer being the resin of interest and the other being a protective layer for packaging. To remove the protective layer, place a piece of scotch tape on both sides of a pre-cut piece such that they overhang and adhere together. Now, tear the pieces of tape apart and continue tearing until the two layers separate.
4. Place the piece of Surlyn on top of your anode with the pre-cut hole in it over the square of dye-coated Titania:SWNT materials you created last time. Using two clips, clip a piece of teflon on top of the Surlyn. Place this "sandwich" of materials you've made into a 100 C drying oven for 10 minutes. (This is to melt the Surlyn to the surface of the anode.)
5. Allow your Surlyn coated anode to cool to room temperature. To now complete the solar cell, pipette 30 microliters of Electrolyte solution, which contains the Iodide redox mediator that will recycle electrons to the dye, on top of the dye-coated square. Next, use two clips to clip a piece of Platinum sputtered glass on top of the electrolyte solution containing anode (Prior to clipping it, you should wrap copper tape around both ends of the platinum coated glass) Your completed solar-cell should look like the picture seen to the right.

Part 2: Testing of Solar Conversion Efficiency