Induced absorption and spontaneous emission due to biexciton in two-dimensional semiconductor (CH3C6H4CH2NH3)2PbBr4 single crystal

Nanocrystalline/microcrystalline materials based on lead-halide units

“…527, 406 and 327 nm, respectively. 6,8,9,[11][12][13] The spectra of these compounds in the particulate form do not show any considerable differences from those of the bulk compounds. 1,4,5,34 However, the PL-spectra of the bulk 3D crystals, such as CH 3 NH 3 PbI 3 , CH 3 NH 3 PbBr 3 and CH 3 NH 3 PbCl 3 , show PL-bands at ca.…”

“…; M ¼ Pb, Sn; X ¼ Cl, Br, I) behave as two-dimensional (2D) semiconducting systems. [4][5][6]11,12,15,16,[28][29][30][31][32][33][34][35] Compounds of the type (SC)MX 3 (SC ¼ CH 3 NH 3 , Cs, K, etc.) behave as three-dimensional (3D) semiconducting systems.…”

Giant and Tunable Optical Nonlinearity in Single‐Crystalline 2D Perovskites due to Excitonic and Plasma Effects

“…Under intense optical fields, the exciton–exciton interactions in the RPP quantum wells can lead to a situation where the excitons cannot be modeled as noninteracting ideal bosons, and thus they contribute to the NLO response . NLO processes, including the excitation of dipole‐forbidden triplet exciton, biexciton, and triexciton, third‐harmonic generation (THG), and four‐wave mixing, have been demonstrated for RPPs. However, these NLO studies have been conducted mainly on bulk single crystals and polycrystalline films.…”

Impact of Dark Excitons on the Population and Relaxation Kinetics of Two-Dimensional Biexcitons in [CH3(CH2)3NH3]2Pb1–xMnxBr4 (x = 0–0.09)

“…Optical excitation of two-dimensional (2D) semiconducting materials is essentially excitonic at room temperature owing to the strong Coulomb interaction between an electron and a hole under quantum and dielectric confinements. − Therefore, 2D systems derived from transition metal dichalcogenides (TMDs) − and organic–inorganic halide perovskites , have attracted great attention for investigating many-body excitonic effects and exciton-related optoelectronic applications under the grand theme of enhanced light–matter interaction. For example, 2D excitons formed with binding energies of a few hundred meV have been reported from atomically thin MX 2 (M = Mo and W; X = S and Se) ,,, and 2D Ruddlesden–Popper series of halide perovskites, A 2 A′ n –1 Pb n Q 3 n +1 (A = BA = CH 3 (CH 2 ) 3 NH 3 , PEA = C 6 H 5 (CH 2 ) 2 NH 3 ; A′ = MA = CH 3 NH 3 ; Q = I and Br; n = 1–5). ,− The latter is particularly interesting because the strong 2D effects can be manifested even in the three-dimensional (3D) framework, i.e., bulk single crystals, in which an atomic-scale multiple-quantum-well structure is formed by repeating the A-site organic cations (barriers) and the perovskite cages (wells). Strong Coulomb interactions in these systems naturally lead to the formation of multiexcitonic complexes such as charged excitons (trions), − biexcitons (excitonic molecules), ,,− and charged biexcitons (exciton–trion bound states) at much higher temperatures compared with those in conventional 3D semiconductors.…”

“…For example, 2D excitons formed with binding energies of a few hundred meV have been reported from atomically thin MX 2 (M = Mo and W; X = S and Se) ,,, and 2D Ruddlesden–Popper series of halide perovskites, A 2 A′ n –1 Pb n Q 3 n +1 (A = BA = CH 3 (CH 2 ) 3 NH 3 , PEA = C 6 H 5 (CH 2 ) 2 NH 3 ; A′ = MA = CH 3 NH 3 ; Q = I and Br; n = 1–5). ,− The latter is particularly interesting because the strong 2D effects can be manifested even in the three-dimensional (3D) framework, i.e., bulk single crystals, in which an atomic-scale multiple-quantum-well structure is formed by repeating the A-site organic cations (barriers) and the perovskite cages (wells). Strong Coulomb interactions in these systems naturally lead to the formation of multiexcitonic complexes such as charged excitons (trions), − biexcitons (excitonic molecules), ,,− and charged biexcitons (exciton–trion bound states) at much higher temperatures compared with those in conventional 3D semiconductors. For example, early studies reported very large values of biexciton binding energy (ϕ) in monolayer WSe 2 (∼52 meV) and BA 2 PbBr 4 (∼60 meV), respectively.…”