Impact of Surfaces on Photoinduced Halide Segregation in Mixed-Halide Perovskites

By Rebecca A. Belisle, Kevin A. Bush, Luca Bertoluzzi, Aryeh Gold-Parker, M. Toney, M. McGehee. ACS Energy Letters, 2018

232 citations recorded by the source corpus.

Photoinduced halide segregation currently limits the perovskite chemistries available for use in high-bandgap semiconductors needed for tandem solar cells. Here, we study the impact of post-deposition surface modifications on photoinduced halide segregation in methylammonium lead mixed-halide perovskites. By coating a perovskite surface with the electron-donating ligand trioctylphosphine oxide (TOPO), we are able to both reduce nonradiative recombination and dramatically slow the onset of halide segregation in CH3NH3PbI2Br films. This result, coupled with the observation that the rate of halide segregation can be tuned by varying the selective contact, provides a direct link between surface modifications and photoinduced trap formation. On the basis of these observations, we discuss possible mechanisms for photoinduced halide segregation supported by drift-diffusion simulations. This work suggests that improved understanding and control of perovskite surfaces provides a pathway toward stable and high-perf...

Subfields: Electrical and Electronic Engineering, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/24acdb1a3b885965ae11d5a8602f0c8356d27018

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Electrical and Electronic Engineering

1. M. McGehee
2. Edward H. Sargent
3. R. Prasanna
4. Caleb C. Boyd
5. K. Zhu
6. B. O'Regan
7. Yi Hou
8. D. Xue

In Materials Chemistry

1. M. McGehee
2. R. Prasanna
3. Caleb C. Boyd
4. K. Zhu
5. B. O'Regan
6. Edward H. Sargent
7. Yi Hou
8. D. Xue

Citations in the corpus

• Efficient tandem solar cells with solution-processed perovskite on textured crystalline silicon (2020, background): “demonstrating that charge accumulation and carrier trapping at perovskite surfaces are drivers of photoinduced halide segregation, and that efficiently passivating the perovskite surfaces suppresses phase segregation and stabilized wide-band gap perovskites (25).”
• Mobile Ion Concentration Measurement and Open-Access Band Diagram Simulation Platform for Halide Perovskite Solar Cells (2020, background): “8 Bowring et al. also explained that high electric fields at reverse bias could trigger chemical reactions and a quasi-reversible efficiency drop.”