We have shown that inverted BHJ devices made with rapidly grown ZnO hole blocking layers using atmospheric atomic layer deposition (AALD) give device performances that are comparable with the best inverted P3HT:PCBM BHJ devices reported to date. Working devices with good, but lower performance were obtained without any post-annealing of the as-grown AALD ZnO. On the other hand, these unannealed AALD ZnO films are suitable for making flexible, plastic substrate solar cells. A compromise between device performance and suitability for making plastic substrate solar cells was achieved by post-annealing the ZnO films at 150 °C. The AALD ZnO fulfils the properties required for good hole blocking layers: the films are compact, have a high electron mobility, have up to 100% visible light transmittance, good blend wettability and very good device stability over time. In addition, the deposition process occurs under atmospheric conditions and has the potential to be implemented in a roll-to-roll process. AALD ZnO films are therefore highly suited as multifunctional components for inverted BHJ devices.
ZnO films
post-annealing
150 °C
°C
films
visible light transmittance
up to 100%
%