Hi, i would like to know will the humidity (40-60%) of the room be detrimental to the MAI powder when weighting on the analytical balance? is the moisture sensitivity reduced when MAI is quickly dissolved in DMF and DMSO? Can I even open the MAI bottle in ambient air to perform weighting in the first place? Same question goes for PbI. Thank you.
Thank you Soo for reporting the exact procedure of handling the MAI for preparing the perovskite material. It is really useful.
However, when fabricating electronic devices there is string precautions to always follow:
Use the highest purity material
keep the material purity during your handling or processing.
The two mentioned precautions summarize what do you reported.
It is known that any contamination will detract the final product and therefore one has to switch off all possible contaminants during the handling and processing until the device is encapsulated.
Therefore one works in clean boxes.
Best wishes
Ideally you should weigh your air sensitive materials inside the controlled atmosphere. To do that, a simple notrogen filled glove box can do the job well. For example, the basic glovebox from Sigmaaldrich is a good choice to put a balance inside. Please see the following link
https://www.sigmaaldrich.com/catalog/substance/plaslabsbasicglovebox1234598765?lang=en®ion=GB
After weighing, you should seal the materials inside a bottle or sample vial. Your solutions have to be prepared inside a different glovebox if possible. Hope it helps.
Here to answer my own question after doing some lab work. Yes and No. You can transfer approximate amount of MAI and PbI from their stock bottles to a secondary bottle and take it out for weight measurement at 40-60% RH ambient condition, but it only works for the first immediate measurement.
After that if you close the secondary bottle at ambient environment, subsequent use will fail. The solution will become turbid/cloudy regardless of how long you stir and heat and the film deposited does not resemble the color of perovskite layer. This was also reported by the following work:
Ciro, J., Betancur, R., Mesa, S., Jaramillo, F., 2017. High performance perovskite solar cells fabricated under high relative humidity conditions. Sol. Energy Mater. Sol. Cells 163, 38–42.
The MAI and some reacted MAI iodine derivatives can still fully dissolved in Isopropanol and convert unreacted PbI spin-coated from the turbid/cloudy solution into Perovskite, at least that is what I observed.
I was lucky enough to take out only a little of the powders into secondary bottle, so my stock bottles are still safe inside the glovebox. You can dissolve the MAI and PbI in the argon glovebox, take it out and spin-coat at ambient air and it will form perovskite film, but make sure to finish the prepared solution the same day.
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