The Optical Spectrum of Single-Crystal (CH3NH3)PbBr3 Cleaved in Ultrahigh Vacuum

Journal article
(Original article)


Publication Details

Author(s): Niesner D, Schuster O, Wilhelm M, Levchuk I, Osvet A, Shrestha S, Batentschuk M, Brabec C, Fauster T
Journal: Physical Review B
Publication year: 2017
ISSN: 2469-9950
Language: English


Abstract


We measure temperature-dependent one-photon and two-photon induced photoluminescence from (CH3NH3)PbBr3 single crystals cleaved in ultrahigh vacuum. An approach is presented to extract absorption spectra from a comparison of both measurements. Cleaved crystals exhibit broad photoluminescence spectra. We identify the direct optical band gap of 2.31 eV. Below 200 K, the band gap increases with temperature, and

it decreases at elevated temperature, as described by the Bose-Einstein model. An excitonic transition is found 22 meV below the band gap at temperatures <200 K. Defect emission occurs at photon energies <2.16 eV. In addition, we observe a transition at 2.25 eV (2.22 eV) in the orthorhombic (tetragonal and cubic) phase. Below 200 K, the associated exciton binding energy is also 22 meV, and the transition redshifts at higher temperature.

The binding energy of the exciton related to the direct band gap, in contrast, decreases in the cubic phase. High-energy emission from free carriers is observed with higher intensity than reported in earlier studies. It disappears after exposing the crystals to air.



FAU Authors / FAU Editors

Batentschuk, Miroslaw PD Dr.-Ing.
Institute Materials for Electronics and Energy Technology (i-MEET)
Brabec, Christoph Prof. Dr.
Institute Materials for Electronics and Energy Technology (i-MEET)
Fauster, Thomas Prof. Dr.
Lehrstuhl für Festkörperphysik
Levchuk, Ievgen
Institute Materials for Electronics and Energy Technology (i-MEET)
Niesner, Daniel Dr.
Lehrstuhl für Festkörperphysik
Osvet, Andres Dr.
Institute Materials for Electronics and Energy Technology (i-MEET)
Schuster, Oskar
Lehrstuhl für Festkörperphysik
Shrestha, Shreetu
Institute Materials for Electronics and Energy Technology (i-MEET)


Research Fields

Lead halide perovskites
Lehrstuhl für Festkörperphysik
Neue Materialien und Prozesse
Research focus area of a faculty: Technische Fakultät


How to cite

APA:
Niesner, D., Schuster, O., Wilhelm, M., Levchuk, I., Osvet, A., Shrestha, S.,... Fauster, T. (2017). The Optical Spectrum of Single-Crystal (CH3NH3)PbBr3 Cleaved in Ultrahigh Vacuum. Physical Review B.

MLA:
Niesner, Daniel, et al. "The Optical Spectrum of Single-Crystal (CH3NH3)PbBr3 Cleaved in Ultrahigh Vacuum." Physical Review B (2017).

BibTeX: 

Last updated on 2019-18-03 at 10:02