Why does it damage the perovskite? I see some researchers are using ebeam evaporation for gold deposition. Please see this article:

https://www.researchgate.net/publication/313242587_Efficient_and_stable_solution-processed_planar_perovskite_solar_cells_via_contact_passivation

Toronto group with efficiency above 20%.

Article Efficient and stable solution-processed planar perovskite so...

Best way out is to compare both thermal and e-beam evaporation, and come to the conclusion which one is the best suited for your case.

In the case of e-beam evaporation, in case you sample are close to the source, there every chance of bombardment with highly energetic specie arriving on the substrate having you perovksite coatings. Whereas in the case of thermal evaporation , the process involves slow evaporation, and less likelyhood of energetic specie arriving on the substrate.

Sreenivas.

Thank you. We don't have access to thermal evaporator. Also, the deposition rate was slow (like 0.2-0.5 A/Sec) to not damage the HTM and perovskite. Also, I said the distance is more than 50cm and samples don't get hot.

If thermal evaporation is ok, I would expect e-beam to be ok, too.  The evaporation mechanism is the same, but e-beam creates a smaller heated area (just where the e-beam hits if sample is insulating, or just the sample if it is conducting; i.e., just the gold will be hot).  So the substrate will receive less heating with e-beam.  None of the e-beam at all will irradiate the substrate, so you are safe from that.  If you are worried about evaporating metal being ionized by the beam, then being accelerated to the substrate.... don't worry about that.  If both the e-beam hearth and the substate are grounded there will be no accelerating voltage, so any ions formed will be attracted to the e-beam.  If you can't ground the substrate, that is fine, and few ions hitting it, will quickly build up a charge that repells any more ions.  And again, there is no significant voltage difference to accelerate anything toward the substrate.

Ebeam evaporation will not affect Perovskite, infact you can even go to higher rates as high as 15-20 A/s. From your IV curve looks like you have issues with one of the transport layers. 

Thank you Li, Sreenivas, Boyer, and Hisham. I ll provide new samples and update here. BTW, the cross-sectional FIB-SEM image is attached.

The e-beam evaporation works fine if the chamber is big enough so that samples do not get hot. The problem here with my samples was hidden in the compact TiO2 layer. We solved this issue. Thank you for your comments.