Rev. Laser-Induced Amp. Emission

Reversible Laser-Induced Amplified Spontaneous Emission from Coexisting Tetragonal and Orthorhombic Phases in Hybrid Lead Halide Perovskites

The photoluminescence in a lead halide perovskite is measured for different temperatures (5–300 K) and excitation fluences (21–1615 µJ cm−2). It is found that amplifi ed spontaneous emission (ASE) is observed for an excitation density larger than about 1 × 1018 cm−3 for both the tetragonal phase above 163 K and the orthorhombic phase below about 163 K. The fluence that is required to obtain this excitation density depends on temperature and phase since the nonradiative decay of excitations is temperature activated with different activation energies of 85±20 and 24±5 meV for the tetragonal and orthorhombic phase, respectively. The ASE from the tetragonal phase—usually prevailing at temperatures above about 163 K—can also be observed at 5 K, in addition to the ASE from the orthorhombic phase, when the sample is previously exposed to a fl uence exceeding 630 µJ cm−2 at a photon energy of 3.68 eV. This additional ASE can be removed by mild heating to 35 K or optically, by exposing the sample by typically a few seconds with a fl uence around 630 µJ cm−2. The physical mechanism underlying this optically induced phase transition process is discussed. It is demonstrated that this phase change can, in principle, be used for an all-optical “write–read–erase” memory device.

Fabian Panzer, Sebastian Baderschneider, Tanaji P. Gujar, Thomas Unger, Sergey Bagnich, Marius Jakoby, Heinz Bässler, Sven Hüttner, Jürgen Köhler, Ralf Moos, Mukundan Thelakkat, Richard Hildner and Anna Köhler, 2016.
University of Bayreuth, 95440 Bayreuth , Germany

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