With strongly bound and stable excitons at room temperature, single-layer, two-dimensional organic-inorganic hybrid perovskites are viable semiconductors for light-emitting quantum optoelectronics applications. In such a technological context, it is imperative to comprehensively explore all the factors - chemical, electronic, and structural - that govern strong multiexciton correlations. Here, by means of two-dimensional coherent spectroscopy, we examine excitonic many-body effects in pure, single-layer (PEA)2PbI4 (PEA = phenylethylammonium). We determine the binding energy of biexcitons - correlated two-electron, two-hole quasiparticles - to be 44±5 meV at room temperature. The extraordinarily high values are similar to those reported in other strongly excitonic two-dimensional materials such as transition-metal dichalcogenides. Importantly, we show that this binding energy increases by ∼25% upon cooling to 5 K. Our work highlights the importance of multiexciton correlations in this class of technologically promising, solution-processable materials, in spite of the strong effects of lattice fluctuations and dynamic disorder.
Stable biexcitons in two-dimensional metal-halide perovskites with strong dynamic lattice disorder / Thouin F.; Neutzner S.; Cortecchia D.; Dragomir V.A.; Soci C.; Salim T.; Lam Y.M.; Leonelli R.; Petrozza A.; Kandada A.R.S.; Silva C.. - In: PHYSICAL REVIEW MATERIALS. - ISSN 2475-9953. - ELETTRONICO. - 2:3(2018), pp. 034001.1-034001.10. [10.1103/PhysRevMaterials.2.034001]
Stable biexcitons in two-dimensional metal-halide perovskites with strong dynamic lattice disorder
Cortecchia D.;
2018
Abstract
With strongly bound and stable excitons at room temperature, single-layer, two-dimensional organic-inorganic hybrid perovskites are viable semiconductors for light-emitting quantum optoelectronics applications. In such a technological context, it is imperative to comprehensively explore all the factors - chemical, electronic, and structural - that govern strong multiexciton correlations. Here, by means of two-dimensional coherent spectroscopy, we examine excitonic many-body effects in pure, single-layer (PEA)2PbI4 (PEA = phenylethylammonium). We determine the binding energy of biexcitons - correlated two-electron, two-hole quasiparticles - to be 44±5 meV at room temperature. The extraordinarily high values are similar to those reported in other strongly excitonic two-dimensional materials such as transition-metal dichalcogenides. Importantly, we show that this binding energy increases by ∼25% upon cooling to 5 K. Our work highlights the importance of multiexciton correlations in this class of technologically promising, solution-processable materials, in spite of the strong effects of lattice fluctuations and dynamic disorder.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.