| Autor: |
Niesner, Daniel, Wilhelm, Max, Levchuk, Ievgen, Osvet, Andres, Shrestha, Shreetu, Batentschuk, Miroslaw, Brabec, Christoph, Fauster, Thomas |
| Rok vydání: |
2016 |
| Předmět: |
|
| Zdroj: |
Phys. Rev. Lett. 117, 126401 (2016) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevLett.117.126401 |
| Popis: |
As they combine decent mobilities with extremely long carrier lifetimes, organic-inorganic perovskites have opened a whole new field in opto\-electronics. Measurements of their underlying electronic structure, however, are still lacking. Using angle-resolved photoelectron spectroscopy, we measure the valence band dispersion of single-crystal CH$_3$NH$_3$PbBr$_3$. The dispersion of the highest energy band is extracted applying a modified leading edge method, which accounts for the particular density of states of organic-inorganic perovskites. The surface Brillouin zone is consistent with bulk-terminated surfaces both in the low-temperature orthorhombic and the high-temperature cubic phase. In the low-temperature phase, we find a ring-shaped valence band maximum with a radius of 0.043 {\AA}$^{-1}$, centered around a 0.16 eV deep local minimum in the dispersion of the valence band at the high-symmetry point. Intense circular dichroism is observed. This dispersion is the result of strong spin-orbit coupling. Spin-orbit coupling is also present in the room-temperature phase. The coupling strength is one of the largest reported so far. |
| Databáze: |
arXiv |
| Externí odkaz: |
|
