At HOPV 13 Conference Henry Snaith presented interesting ideas about the exciting devlopment of mesoscopic solar cells based on perovskite absorbers. Snaith was the one to have the idea to remove the TiO2 while preparing the mesoscopic solar cells, using instead mesoporous alumina , where electron cannot be injected because of energetic reasons. These results where published in the Science paper with Miyasaka last year. Today Henry proposed the view that there is a major change on the field of mesoscopic solar cells, which could evolve to either thin film or mesoscopic heterojunction. Thefore a number of questions appear now, and will be studied in the near future together with the outstanding results of Grätzel’s group communicated below. Since the perovskite looks an efficient transporter of electrons and holes with a reasonable lifetime, is TiO2 needed or important? More generally, is a separation into electron and hole conductors needed, or just selective contacts at the electrodes? How thick will be the perovskite absorber, will it form a thin layer covering a mesostructure, or a thick layer that carries both electrons and holes?
The changes of mesoscopic solar cells:
perovskite MSSC, with or without TiO2
pin thin film?
porous perovskite pn junction?