RESUMEN
Lead halide perovskites have been promising platforms for micro- and nanolasers. However, the fragile nature of perovskites poses an extreme challenge to engineering a cavity boundary and achieving high-quality (Q) modes, severely hindering their practical applications. Here, we combine an etchless bound state in the continuum (BIC) and a chemically synthesized single-crystalline CsPbBr3 microplate to demonstrate on-chip integrated perovskite microlasers with ultrahigh Q factors. By pattering polymer microdisks on CsPbBr3 microplates, we show that record high-Q BIC modes can be formed by destructive interference between different in-plane radiation from whispering gallery modes. Consequently, a record high Q-factor of 1.04 × 105 was achieved in our experiment. The high repeatability and high controllability of such ultrahigh Q BIC microlasers have also been experimentally confirmed. This research provides a new paradigm for perovskite nanophotonics.
RESUMEN
Compared with their 3D counterparts, layered 2D Ruddlesden-Popper perovskites (2D RPPs) with the formula of (A')2A n-1Pb nX3 n+1 exhibit improved photo and moisture stability. To develop flexible single-crystalline electronics and wearable devices, cost-effective growth of large-area single crystals of 2D RPPs with large lateral size, ultrathin thickness, parallel orientation, and well-defined and controlled n values are highly desirable, but it remains still a challenge. Here, we modified the space-confined aqueous solution growth method to fabricate single-crystalline films of (BA)2(MA) n-1Pb nX3 n+1 and n = 1, 2, 3, respectively, with the lateral size reaching millimeter and thickness about 400-1000 nm. Moreover, the quantum well layers are found to be parallel to the substrate, well suitable for lateral transport requirement. We successfully integrated ultrathin single crystals of (BA)2(MA) n-1Pb nX3 n+1 ( n = 1-3) into a metal-semiconductor-metal two-terminal photodetector. The photoresponsive wavelength range was extended from 525 nm for n = 1 and 590 nm for n = 2 to 630 nm for n = 3 as a result of the reduced exciton band gap. The device of n = 2 single crystals shows the highest responsivity of 2.96 A/W and a detectivity of 1013 jones, while the device of n = 3 shows the lowest dark current 10-14 A, and therefore, its on/off ratio reaches 2862 at the bias voltage of 1 V.
RESUMEN
We demonstrated a stimuli-responsive and chemically switchable organic microbelt laser through reversible protonation-deprotonation reactions. The parent microbelt cavity together with the optically allowed 0-1 transition of H-aggregates enables a microlaser to operate at 585 nm. Upon HCl vapor treatment, the protonation of surface molecules shifts the lasing wavelength to 560 nm, generating an intensity contrast ratio >105, accompanied by a sharp color change from orange (deprotonated) to green (protonated). When treated with HCl-NH3 vapor, the protonation-deprotonation reactions lead to a reversible microlaser switch between 585 nm and 560 nm with good reproducibility and photostablity, making them attractive in high-throughput chemical and biological sensing applications.
RESUMEN
Fabrication of semiconductor nanowire laser arrays is very challenging, owing to difficulties in direct monolithic growth and patterning of III-V semiconductors on silicon substrates. Recently, methylammonium lead halide perovskites (MAPbX3, X = Cl, Br, I) have emerged as an important class of high-performance solution-processed optoelectronic materials. Here, we combined the "top-down" fabricated polydimethylsiloxane rectangular groove template (RGT) with the "bottom-up" solution self-assembly together to prepare large-scale perovskite nanowire (PNW) arrays. The template confinement effect led to the directional growth of MAPbX3 along RGTs into PNWs. We achieved precise control over not only the dimensions of individual PNWs (width 460-2500 nm; height 80-1000 nm, and length 10-50 µm) but also the interwire distances. Well-defined dimensions and uniform geometries enabled individual PNWs to function as high-quality Fabry-Perot nanolasers with almost identical optical modes and similarly low-lasing thresholds, allowing them to ignite simultaneously as a laser array. Optical tests demonstrated that PNW laser arrays exhibit good photostabillity with an operation duration exceeding 4 × 107 laser pulses. Precise placement of PNW arrays at specific locations makes our method highly compatible with lithographic techniques, which are important for integrating PNW electronic and photonic circuits.
RESUMEN
A polydimethylsiloxane cylindrical-hole-template-confined solution-growth method is developed to fabricate densely packed CsPbCl3-x Br x microdisk laser arrays. Furthermore, a strategy to integrate multicolored microdisk laser (MDL) arrays is demonstrated that simultaneously lase in the deep blue, blue, cyan, and green by means of gas-phase replacement of Cl by Br from initial CsPbCl3 MDLs in HBr vapor.
