Third-Order Optical Nonlinearity Due to Excitons and Biexcitons in a Self-Organized Quantum-Well Material (C₆H₁₃NH₃)₂PbI₄

Abstract

Third-order optical nonlinearity around the exciton resonance in (C6H13NH3)2PbI4 was measured using time-integrated and spectrally-resolved four-wave-mixing (FWM) techniques. For excitation below the exciton resonance, biexciton contribution to the FWM signals was observed. The dephasing energy of the biexcitons was estimated to be larger than 10 meV.

Exciton–exciton interaction in an inorganic–organic layered semiconductor, (C6H5C2H4NH3)2PbI4

“…The exciton decay rate, g r , is twice as large as that reported previously [11], probably because of the sample dependence of the nonradiative decay rate. The relaxation rate of the excitonic spin polarization, 2g s , is consistent with the value reported for a similar type of semiconductor, (C 6 H 13 NH 3 ) 2 PbI 4 [10].…”

“…The phase-relaxation time of the exciton is presumably 300-500 fs [10], but coherent transients, such as a nutation, were not observed. For the induced absorption due to the excitonic molecule, absorption is observed at 100 fs in s + s À , but not in s + s + .…”

Influence of dielectric confinement on excitonic nonlinearity in inorganic-organic layered semiconductors

“…Yet, the relaxation in the angular momentum space here is more reasonably ascribed to the exciton-phonon scattering, considering that the obtained value for C6-PbI 4 is close to the dephasing rate measured by the degenerate four-wavemixing experiment under the weak excitation regime. 40 Unfortunately, a four-wave-mixing experiment has not been performed for PhE-PbI 4 . On the assumption that a phonon scattering makes an exciton relax in the angular momentum space, we have no concrete explanation for the larger dephasing rate in C6-PbI 4 than that in PhE-PbI 4 .…”

Synthesis, vibrational and optical properties of a new three-layered organic–inorganic perovskite (C4H9NH3)4Pb3I4Br6

“…These layered organic inorganic perovskites with the general formula (C n ) 2 PbX 4 (C n ¼ C n H 2n+1 HN 3 , X ¼ Br, I), can be regarded as semiconductor/insulator multiple quantum well systems consisting of lead halide semiconductor layers sandwiched between organic ammonium insulator layers [8][9][10][11][12][13]. Owing to their large binding energy, stable excitons are formed, exhibiting attractive optical properties such as efficient luminescence and high optical nonlinearity [14,15]. The strong photoluminescence in the PbX 2 (X ¼ I or Br) based perovskite systems, and the high carrier mobility in the plane of the inorganic sheets, suggest the possible use of these materials in optical devices such as electroluminescent (EL) diodes [16].…”