Coarse and fine-tuning of lasing transverse electromagnetic modes in coupled all-inorganic perovskite quantum dots

Abstract

Inorganic perovskite lasers are of particular interest, with much recent work focusing on Fabry-Pérot cavity-forming nanowires. We demonstrate the direct observation of lasing from transverse electromagnetic (TEM) modes with a long coherence time ∼ 9.5 ps in coupled CsPbBr3 quantum dots, which dispense with an external cavity resonator and show how the wavelength of the modes can be controlled via two independent tuning-mechanisms. Controlling the pump power allowed us to fine-tune the TEM mode structure to the emission wavelength, thus providing a degree of control over the properties of the lasing signal. The temperature-tuning provided an additional degree of control over the wavelength of the lasing peak, importantly, maintained a constant full width at half maximum (FWHM) over the entire tuning range without mode-hopping.

Challenges, Opportunities, and Prospects in Metal Halide Perovskites from Theoretical and Machine Learning Perspectives

“…), and X is halide (X = Cl, Br, and I). [ 1–6 ] As many types of metal halide materials have been explored, the MHPs now include other types of metal halide structures as well, such as 2D Ruddlesden–Popper perovskite, [ 7 ] 0D metal halides, [ 4 ] and lead‐free double perovskites. [ 8,9 ] MHPs have shown a great promise for various applications, including solar cells, [ 3 ] light emitting diodes (LEDs), [ 4,7,10–12 ] transistors, [ 5 ] and lasers.…”

“…[ 8,9 ] MHPs have shown a great promise for various applications, including solar cells, [ 3 ] light emitting diodes (LEDs), [ 4,7,10–12 ] transistors, [ 5 ] and lasers. [ 6 ] To name a few, MHPs recently achieved the power conversion efficiency (PCE) over 25% [ 1,2 ] (up to 25.8 % [ 3 ] ) as a single junction solar cell, which could be an alternative to the conventional solar cell materials. Also, MHPs showed excellent photoluminescence (PL) properties like broad color gamut and high PL quantum efficiencies.…”

“…), and X is halide (X = Cl, Br, and I). [1][2][3][4][5][6] As many types of metal halide materials have been explored, the MHPs now include other types of metal halide structures as well, such as 2D A high dimensional space of control parameters, such as compositions, [27] structures, [7,28,29] solvents, [30,31] and thermodynamic conditions, is another challenge in discerning the correlations between microscopic and macroscopic properties of MHPs. [32,33] Since most of the synthesis routes of MHPs rely on solution-based processes, the synthesis of MHPs is hard to control and optimize.…”

1-nm linewidth room temperature single-photon source from optical microcavity-embedded CsPbI3 perovskite quantum dots

“…We calculated the decay lifetime using a monoexponential fit of the TRPL curve typical of the transition rate dynamics in two-level systems like PQDs excited at low powers 15,21 . We note that the fast coherent portion of the PL signal is more than 2.5 orders of magnitude more intense than the long-lived residual tail of the emission, attributed to delayed carrier recombination during thermalisation and trapping 27 . Detector dark counts account for the flat non-zero intensity segment of the delayed tail of the emission and contribute to the residual coincidence counts during single-photon counting.…”

Resonantly Pumped Bright-Triplet Exciton Lasing in Cesium Lead Bromide Perovskites

“…This might appear to be problematic for the efficiency of optoelectronics given the three-to-one prevalence of triplets over singlets in a range of optical materials, including semiconductors and lead halide perovskites. , Recent reports , overturn this view by showing that the emission intensity from fast triplets in lead halide perovskite nanocrystals (PNCs) is not only bright, but accounts for why these materials can be up to 10× brighter than other semiconductors. These are encouraging results for photovoltaics, single-photon sources, wavelength-tunable nanolasers, − nonlinear and spintronic devices, and optoelectronic applications . Unlike in other semiconductors, the heavy ions in CsPbBr 3 lead to strong coupling between the spin and orbital angular momenta of holes ( j h = 1/2) and electrons (where j e = ±1/2, since the electronic state is doubly degenerate due to the stronger spin–orbit term in the conduction band) such that only the total angular momentum ( J = j h + j e ) is conserved.…”