|Effect of ALD Reactants on Blistering of Aluminum Oxide Films on Crystalline Silicon|
|Shuo Li1,2, Päivikki Repo1, Guillaume von Gastrow1, Yameng Bao1, Hele Savin1
1Aalto university, Espoo, Finland
/2Beneq Oy, Vantaa, Finland
Abstract — Atomic layer deposited (ALD) aluminum oxide (Al2O3) has in recent years proven to be a promising surface passivation material for crystalline silicon solar cells. However, blistering in Al2O3 films is a common problem deteriorating the surface passivation quality. Here, blistering is studied from material aspects utilizing the unique nature of ALD to artificially engineer material properties within one single process. We show how thicker films, higher annealing temperatures and longer annealing times lead to more severe blistering and demonstrate how blistering can be avoided by either engineering the film-substrate interface or by modifying the film composition.