Robust Molecular Dipole‐Enabled Defect Passivation and Control of Energy‐Level Alignment for High‐Efficiency Perovskite Solar Cells
Abstract
The ability to passivate defects and modulate the interface energy‐level alignment (IEA) is key to boost the performance of perovskite solar cells (PSCs). Herein, we report a robust route that simultaneously allows defect passivation and reduced energy difference between perovskite and hole transport layer (HTL) via the judicious placement of polar chlorine‐terminated silane molecules at the interface. Density functional theory (DFT) points to effective passivation of the halide vacancies on perovskite surface by the silane chlorine atoms. An integrated experimental and DFT study demonstrates that the dipole layer formed by the silane molecules decreases the perovskite work function, imparting an Ohmic character to the perovskite/HTL contact. The corresponding PSCs manifest a nearly 20 % increase in power conversion efficiency over pristine devices and a markedly enhanced device stability. As such, the use of polar molecules to passivate defects and tailor the IEA in PSCs presents a promising platform to advance the performance of PSCs.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 30, 2021
- Source ID
- 10.1002/ange.202105512
Entities
People
- Bing Wang
- Hong Li
- Jean‐luc Brédas
- Meng Zhang
- Qingqing Dai
- Zhigang Zou
- Zhiqun Lin
Organizations
- Georgia Tech
- Nanjing University
- National Science Foundation
- Office of Naval Research
- University of Arizona