Two-Photon Lasing from Two-Dimensional Homologous Ruddlesden–Popper Perovskite with Giant Nonlinear Absorption and Natural Microcavities

Abstract

Two-dimensional Ruddlesden–Popper perovskites (RPPs) with multiple quantum well-like structures, strong excitonic quantum confinement, and high stability are promising optical gain media. However, the lasing from such material with a small number of inorganic well layers is difficult to achieve. Herein, we demonstrate the low-threshold upconversion lasing from the homologous RPP (PEA)2(MA) n −1Pb n I3 n +1 (n = 2 and 3) microflakes with wavelength varies from 598 to 637 nm under 800 nm laser excitation at low temperature (≤153 K). Using the micro Z-scan technique, we discovered that the RPP flakes have a giant two-photon absorption coefficient β as high as 3.6 × 103 cm GW–1, resulting in the effective upconversion transition under two-photon excitation. Furthermore, the self-formation of Fabry–Pérot microcavities provides the support for lasing emission from the n ≥ 2 RPP flakes. Calculation results and microscopic transient absorption measurements reveal that low-threshold lasing is due to the high differential gain coefficient and the suppressed nonradiative Auger recombination rate inside the quantum confinement structures. These properties enable RPPs as potential gain media for developing upconversion microcavity lasers.

Light-Emitting Organic Semiconductor-Incorporated Perovskites: Fundamental Properties and Device Applications

“…Later, He et al replaced the above large organic spacer cations, BA, with PEA (Figure D) and demonstrated multiexciton lasing from n = 3 and even n = 2 single crystals at low temperatures (Figure E–G). Very recently, Gao et al further obtained two-photon pumped lasing emission from (PEA) 2 (MA) n −1 Pb n I 3 n +1 single crystals with n = 2 and 3 (Figure H–J) under 800 nm laser excitation at low temperature (≤153 K). These results together suggest that bulky organic spacer cations play an important role in determining the lasing properties of single crystalline 2D perovskites.…”

“…(F and G) μ-PL spectra and the corresponding log–log plot of integrated emission intensity of an n = 2 (F) and 3 (G) RP perovskite flake as a function of pumped density P . (H) Lasing spectra of perovskite flakes for n = 2 (left) and n = 3 (right) at 153 and 173 K, respectively (scale bar 5 μm) . (I) Lasing threshold as a function of temperature for n = 2 (black) and n = 3 (red) flakes.…”

“…(I) Lasing threshold as a function of temperature for n = 2 (black) and n = 3 (red) flakes. The characteristic temperatures ( T c ) are fitted . (J) The fwhm of spontaneous emission versus the inverse of temperature, 1/ T , for the perovskite flakes with n = 1, 2, and 3.…”

“…(C) Temperature dependence of lasing thresholds for n = 3, 4, and 5 perovskites . (D) Schematic diagram of a (PEA) 2 (MA) n −1 Pb n I 3 n +1 system ( n = 2 as an example) . (E) The μ-PL pictures of RPPs with n = 2 (top) and 3 (bottom) upon excitation by a 400 nm femtosecond laser above the lasing threshold at 20 K (scale bar 30 μm) .…”

“…(J) The fwhm of spontaneous emission versus the inverse of temperature, 1/ T , for the perovskite flakes with n = 1, 2, and 3. The coupling strength of exciton-LO phonons (Γ LO ) is found to be 182, 51, and 35 meV for n = 1, 2, and 3 RPP flakes, respectively . (A–C) Reproduced with permission from ref .…”