Do you treat the Glass substrate with Oxygen plasma or UV-O3 before deposit the perovskite layer?

Which kind of glass do you use? it is better to use the rare side of ITO or FTO because they have a smother glass surface and could be helpful for perovskite deposition.

@Mahdi Malekshahi Byranvand. Hello sir,

I used FTO as glass substrate n treated it in ultrasonic sonicator before using it. I used equimolar solution of MAI and PbI2 n mixed both in DMF at 60° fot 12hrs. Using single step method I spin coated the solution over FTO substrate... But was not able to get a proper film in several attempts.

Is this because of absence of ETL layer? Can MAPbI3 layer be directly deposited over FTO substrate?

Thank you

Dear Priyanka Roy

I hope you are doing well.

-Regarding your question about the presence of ETL (e.g TiO2 or SnO2)

>> It's better to have it, but not urgent to make a film of MAPbI3.

- Sometimes, I used a microscopic glass (Just cleaned) for making a film for characterization purposes, using an equimolar solution of MAI and PbI2 in DMF/DMSO 4:1 ratio at 100 C for 1h, then spin-coated with two steps 800rpm/10sec, 4000rpm/30sec... and using 100 uL Chlorobenzen as antisolvent... then annealing.

- The difference between deposition on a microscopic glass and on the ETL is the quality and dispersion of the solution on whole area of the glass. But both of them should give a black film of MAPbI3.

- Keep in mind, the whole process should be inside Glovebox. Also, MAI is a very hygroscopic material, it must be stored in the right condition.

- IF the MAI you already used was degradate, you just have a yellow layer of PbI2 with some defects.

Kind regards,

@Mohamed M. Elsenety

Hello sir, Thank alot for sharing your valuable insights.

Can you please tell me,

Is it impossible to get a uniform perovskite layer in open air condition???

Regards

Priyanka

Hello, again Priyanka Roy

- The topic of perovskite is very big and almost more than100 different compositions, and the main problem of all perovskites is long-term stability in ambient conditions.

-Some researchers used inorganic cation such as Cs, or Rb to improve stability and some other form 2D layer on top of absorber 3D perovskite for the same issue.

- There is a lot of strategies on literature that explained everything in this field. But I never read some true paper that succeeds to form stable perovskite (MA/FA)PbI3 in the air conditions without capsulation.

@Mohamed M. Elsenety Thank you so much for help.

Hi Priyanka Roy,

you can refer the following review papers for preparing PSC in open air:

1. High-humidity processed perovskite solar cells (J. Mater. Chem. A, 2020, 8, 10481-10518)

2. Progress in air-processed perovskite solar cells: from crystallization to photovoltaic performance (Mater. Horiz., 2019, 6, 1611-1624)