I201 Nitrogen-Processed Perovskite Solar Cell Fabrication

Glass / ITO / PEDOT:PSS AI 4083 / CH₃NH₃PbI_3-xCl_x / PC₇₀BM / Ca / Al

The summary below outlines the key steps required when processing I201 Perovskite Ink. You can also download this summary as a PDF in order to print and laminate it for use in a clean room.

1. Substrate clean (in air):

• Sonicate ITO substrates for 5 minutes in hot (70 °C) 1% Hellmanex
• Dump-rinse substrates twice in boiling, deionized (DI) water
• Sonicate for 5 mins in IPA. Dump-rinse twice in boiling DI water
• Dry the substrates with nitrogen gun
• Bake the substrates on a hotplate at 120 °C.

2. PEDOT:PSS anode preparation (in air):

• Filter PEDOT:PSS AI 4083 using a 0.45 µm PES filter
• Dispense 35 µl of the filtered PEDOT:PSS solution onto the heated ITO substrate spinning at 6000 rpm for 30s
• Place substrate onto a hotplate at 120 °C
• After all ITO substrates have been coated with a PEDOT:PSS layer, transfer all to a glove box and place onto a hotplate at 120 °C for 20-30 mins
• Remove the substrates from the hotplate and allow to cool at room temperature.

3. Perovskite deposition (in nitrogen glove box):

• Heat I201 ink for 2 hours at 70 °C and then cool to room temperature
• Place the ITO coated substrate (at room temperature) onto the spin-coater and spin the substrate at 4000 rpm (for 30 s)
• Dynamically dispense 30 µl of I201 ink
• Place substrate back onto the hotplate (in the glove box) at 80 °C
• Once all substrates have been coated, anneal for 90 mins
• After 90 mins, use a cleaning swab dipped in a small amount of DMF solvent to wipe the cathode stripe clean
• After cleaning, anneal for an addition 20 – 30 mins at 80 °C to remove any residual DMF solvent
• After this time, remove substrates from the hotplate and cool to room temperature.

4. PC₇₀BM deposition (in nitrogen glove box):

• Prepare a solution of PC₇₀BM at 50 mg / ml in chlorobenzene and stir for 3 to 5 hours
• Place perovskite coated substrate onto the spin-coater and spin at 1000 rpm
• Dispense 20 µl of PC₇₀BM solution onto the substrate (while spinning) and spin for a total time of 30s.

5. Cathode deposition:

• Thermally evaporate a calcium/aluminum cathode (5 and 100 nm respectively) through shadow-mask
• Encapsulate devices using a glass coverslip and encapsulation epoxy
• Expose to UV radiation (350 nm) for 30 mins to cure epoxy.