Enhanced Nucleation of Atomic Layer Deposited Contacts Improves Operational Stability of Perovskite Solar Cells in Air
Abstract
Metal‐halide perovskites show promise as highly efficient solar cells, light‐emitting diodes, and other optoelectronic devices. Ensuring long‐term stability is now a major priority. In this study, an ultrathin (2 nm) layer of polyethylenimine ethoxylated (PEIE) is used to functionalize the surface of C60 for the subsequent deposition of atomic layer deposition (ALD) SnO2, a commonly used electron contact bilayer for p–i–n devices. The enhanced nucleation results in a more continuous initial ALD SnO2 layer that exhibits superior barrier properties, protecting Cs0.25FA0.75Pb(Br0.20I0.80)3 films upon direct exposure to high temperatures (200 °C) and water. This surface modification with PEIE translates to more stable solar cells under aggressive testing conditions in air at 60 °C under illumination. This type of “built‐in” barrier layer mitigates degradation pathways not addressed by external encapsulation, such as internal halide or metal diffusion, while maintaining high device efficiency up to 18.5%. This nucleation strategy is also extended to ALD VOx films, demonstrating its potential to be broadly applied to other metal oxide contacts and device architectures.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 07, 2019
- Source ID
- 10.1002/aenm.201902353
Entities
People
- Axel F Palmstrom
- Benjamin A. Fearon
- Caleb C Boyd
- Eli J Wolf
- James A Raiford
- Joseph J. Berry
- Michael McGehee
- Stacey Bent
Organizations
- National Renewable Energy Laboratory
- National Science Foundation
- Office of Energy Efficiency and Renewable Energy
- Office of Naval Research
- Solar Energy Technologies Office
- Stanford University
- United States Department of Energy
- University of Colorado