Perovskite film fabrication is very easy inside a glove box. Just add 112 mg of MAI and 461 mg of PbI2 in 1 mL DMF. Stirr it overnight at 60-70 degree celcius. Then spin coat it at a speed of 2500 rpm for 30 sec. Anneal it at 100-120 degree for 15 min . You will get thin film of 220 nm.

However you can improve the film quality through different techniques.

1) Antisolvent treatment ( chlorobenzene )

2) solvent engineering ( use mixture of DMF, DMSO or GBL)

3) Modify the speed of spin coating. ( Say 1000 rpm for first 5 sec then 3000 rpm for 25 sec

Go through literature for details.

Dear Hassan

1- 461mg of PbI2 are heated for 10 minutes in order to evaporate any possible humidity within. Then, the bottle’s door is sealed and waited till it totally cooled down. 1202 ul of DMSO is added and heated on hot plate for 5 minutes at 180 degrees till it’s totally dissolved. The solution is slowly shaken to homogenize the solvent with the material.

2- 159mg of MAI are added to an 1166 ul of as-prepared solution after being totally cooled down, and shaken till is dissolved.

3- The solution is spin casted (about 70ul) for 10s at 1000rpm, then 6000 rpm for 30s. At the 15th second of the 2nd part, 100ul of CBZ are dropped as Antisolvant. Annealed for 1hr at 100 degree.

Hi Hassan Shahid

It depends upon the method you are employing to make the perovskite thin film, even you are using spin-coating techniques like a single step or double step spin coating. I basically use the hot casting method to make the perovskite thin-film where I will get higher size perovskite grains compared to other one.

For this, mix 200 mg MAI and 578 mg of PbI2 in 1ml of DMF . Then heat the solution at 100 oC for 2 hrs. In the meantime, heat the substrate (I use microscopic glass coverslips) at 180 oC . Then spin coat the preheated solution in a preheated substrate at 4000rpm for 5 seconds. Then we will get a dark brown colored thin film of perovskite.

Actually I have MaPbI3 as one material ordered from TCI. I have taken its100mg in 1ml of DMSO, and stir it for 1 hour ar room temperature, it gives yellow color precursor, then I spin coat it at 3000RPM for the 30s, and anneal it at 200 for 30mins in a vacuum oven. Result: thin-film not fabricated. Any idea, what should be done in this case to form a good thin film? Thanks

Dear Hassan Shahid ,

Perovskite film formation can be improved with following ways:

1: Make sure the substrate is properly cleaned and does not have any residues or dust particles on it.

2:Try to filter out perovskite precursors with 0.45 micron PTFE filter to remove any solid particles to avoid film breakage during film formation.

3::Using anti-solvent is another good option (it can be Diethylether, Toluene or Chloro-benzene).

4:: Try to vary spin coating speed. Low speed at the start ranges between 1000-2000 rpm during first 30 seconds followed by fast evaporation of the solvents at high rated speed up to 4000 rpm to ensure successful removal of the solvent.

Good Luck!

Best Regards,

A. Sattar

Try to read this paper

To be sure, you should observe the change in color from yellow into brown, this indicates the formation of the perovskite layer.

if not, this means that the MAI did not react with PbI2.

are you sure your using the suitable substrate?

if yes, try to prepare the precursor yourself.

try the method used in this article. totally confirmed Hassan Shahid

regards

Very helpful discussion. Thanks all of you.

In this discussion Abhishek Maiti sir took 112 mg of MAI and 461 mg of PbI2 in 1 mL DMF and Hassan Kassem sir you took 461mg of PbI2 too but 159mg of MAI and there are many other authors took different amount of these materials. My question is what is the basis of taking the amount of materials? Also what is the basis on which peoples are tasking DMF, DMSO solvents? Please clear my doubts....Thanks in advance!