Dear Parag,

This is a very interesting question. I said that the question is very interesting because the tremnology of the HTL and ETL are used with organic heterojunction bulk solar cells.

My answer is as follows:

This solution is already existed with inorganic homojunction cells by the technique called the high low junction or the back surface field where one make nn+ junction to to extract electrons and block holes. It is made also for the p-side with pp+ junction to extract holes and reject electrons from reaching the highly recombining metal semiconductor contact.

Best wishes

https://www.sciencedirect.com/science/article/pii/B9780128095973004260

I agree with Dr. Abdelhalim Zekry