Manufacturing of Large Dye Sensitized Solar Cell at home from Shih Wei Chieh on Vimeo.


Dye-sensitized solar cells (DSSCs) represent an easily manufacturable and cost-effective photovoltaic device and can be done at DIY level. However, its efficiency remains relatively low, posing challenges in meeting commercial standards, primarily due to limitations imposed by the limited conductivity of the FTO or ITO layer within the system. DSSCs offer the advantage of highly customizable patterns and colors for a transparent TiO2 layer, providing opportunities for aesthetically pleasing smart surface designs and is electrically self sufficient. Chemicals utilized in the experiment are mostly purchased from Greatcell Solar, therefore, most of the processes are conventional except the size of the cell in this experiment. The efficiency is about ~5.8V and ~51mA. The low current performance is due to the absence of the parallel circuit here.

The history of the development of the 3rd generation solar cells.
Schematic representation of a TiO2-based DSSC. DSSC, Dye-sensitized solar cell.
Schematic 2 representation of a TiO2-based DSSC. DSSC, Dye-sensitized solar cell.

1. Experiment

1.1 Etching the series circuit on FTO glass

To achieve the necessary voltage, a series circuit is needed to be created with the glass substrates. To achieve this goal, the FTO glass needs to be etched, to create a vertically connection between two FTO glasses. The first picture below illustrates the cross-section of the structure and the positioning of the 12 cells.

About the chemicals employed in this section, firstly, adding 26.3 mL of 38% hydrochloric acid solution to a beaker and then dilute it with water to reach a total volume of 100 mL, to make a 2M HCL solution. The wet photoresist I used here is a product LP8901V6 purchased from Great Eastern Resins Industrial Co. Ltd.(GRECO).

The diagram of the cell manufacturing.
Apply the Kapton tapes to the FTO glass to protect the area wish to be etched. Apply the photoresist to the FTO with glass rod or scraper. Cured the photoresist with UV lamp or sunlight.
After the photoresist is fully cured, remove the Kapton tape to prepare for etching. Due to the uneven coating, my result looks ugly here.

Use a cotton swab to apply zinc powder to areas that do not have wet film photoresist
Apply the HCL solution with a dropper to the zinc powder. The bubbling indicates the etching reaction is happening.
Wait for 10 minutes to let the etching reaction to be completed. Remove the HCL and zinc powder with tower and water run the board to wash away any left over chemicals.
Immerse the etched FTO in sodium hydroxide solution.
After the photoresist is completely dissolved, take out the FTO glass and clean the surface with water and ethanol
Measure the board with multimeter, make sure all 12 conductive strips are completely electrically disconnected.
The successful etched photo-electrode and counter-electrode.

1.2 Sintering of the blocking TiO2 layer and porous TiO2 layer on the photo-electrode

  1. Apply Kapton tape to the glass to create the mask for the TiO2 layer coating. 
  2. Apply the BL-1 paste with a glass coater. This mask will be shared to make the porous layer later. 
  3. Place the photo-electrode in the kiln, ramping up to 125ºC at a rate of 8ºC per minute without removing the Kapton masks. Maintain this temperature for 30 minutes, and then allow it to cool naturally to room temperature. 
  4. Take the cooled glass out and coat the glass again with with 18NR-T paste with a glass coater to make the porous TiO2 layer, then fire it with a ramp rate of 8 ºC per minute to 450ºC. Keep it at 450ºC for 30 minutes before allowing it to cool down naturally to room temperature.

Use the kaptone tape to make the coating mask according to the diagram above.

The kiln for the sintering in this experiment.
Typical TiO2 sintering temperature...
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