Quantum Well Energetics of an n = 2 Ruddlesden–Popper Phase Perovskite
Abstract
A comprehensive investigation of the electronic energy levels of an n = 2 Ruddlesden–Popper phase perovskite is presented. Ultraviolet and inverse photoemission spectroscopies are used to probe the density of states in the valence and conduction bands, respectively, of the quasi‐2D perovskite, butylammonium cesium lead iodide (BA2CsPb2I7). By comparing experimental spectra with calculated projected density of states, the contributions from Cs, Pb, and I to the quantum well states are identified, and distinguished from those of the organic ligand barrier layer. The ionization energy, electron affinity, and exciton binding energy of this material are derived. The energetics of the quantum well structure are discussed in terms of the number of Pb‐halide layers. The resulting energy diagram suggests that a type‐I heterojunction would be formed with the n = 1 BA2PbI4. Finally, surface photovoltage performed via Kelvin probe force microscopy is used to evaluate band bending at the surface of the BA2CsPb2I7 thin films.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 24, 2019
- Source ID
- 10.1002/aenm.201901005
Entities
People
- Antoine Kahn
- Hong Li
- Jean‐luc Brédas
- Qingqing Dai
- Scott Silver
Organizations
- Georgia Research Alliance
- Georgia Tech
- Office of Naval Research
- Princeton University
- United States – Israel Binational Science Foundation