Multimode Lasing in All-Solution-Processed UV-Nanoimprinted Distributed Feedback MAPbI₃ Perovskite Waveguides

Abstract

In this work, we present an all-solution fabrication approach for external second-order 1D distributed feedback (DFB) gratings using soft UV-nanoimprint lithography (UV-NIL) above archetypical methylammonium lead iodide (MAPbI 3 ) perovskite films. This high-throughput method can be carried out in an ambient environment and requires only slightly elevated temperatures as low as 70 °C, gentle imprint pressure, and the use of compatible UV-NIL resin. Under stripe-shaped optical excitation, we observe simultaneously occurring optical phenomena in our high-gain strong-scattering perovskite films, namely amplified spontaneous emission, random lasing, and 1D DFB lasing. In pursuit of distinguishing these mechanisms, we explore far-field emission patterns and output polarization. Additionally, the DFB lasing is hardly attenuated when a thin absorbing indium tin oxide (ITO) film, commonly used as an electrode in fully contacted electrical devices, is inserted between the perovskite film and the DFB grating. As a result, we reproducibly achieve single and multimode, low-threshold (below 100 μJ•cm −2 ), narrow linewidth (below 0.2 nm), and strongly polarized (extinction ratio above 50) optically pumped DFB lasing for MAPbI 3 waveguides with and without an adjacent ITO layer. We believe that the proposed resonator integration approach can be extended toward complete electrically active devices, enabling an alternative integration scheme to achieve current-injection lasing.

The Origin of Threshold Reduction in Random Lasers Based on MoS2/Au NPs: Charge Transfer

“…In contrast to traditional lasers, the feedback amplification in a random laser is not provided by a cavity formed by reflecting elements but by the disorder-induced scattering of light in the random medium [4,5]. As the research on random lasers has improved, significant progress has been made in reducing their thresholds [6][7][8][9], regulating them [10], and finding new materials [11]. Reducing the random laser threshold can increase the efficiency and lifespan of a laser, as well as reduce energy consumption and costs, which will promote the miniaturization and integration of random lasers.…”

Surface Microstructure Engineering in MAPbBr3 Microsheets for Performance-Enhanced Photodetectors

“…In order to obtain high crystallinity films and reduce light loss, perovskite photonic nanostructure films prepared by nanoimprint and nanosphere lithography have been proven to be an economic method. − However, these lithography techniques are incompatible with widely used conventional photolithography for fabricating nanoscale optoelectronic devices. Meanwhile, the performance improvement is still limited by the inherent drawbacks of the perovskite polycrystalline films.…”

Effect of Different Substitutions at the 1,7-Bay Positions of Perylenediimide Dyes on Their Optical and Laser Properties

“…Optically pumped lasers based on solution-processed thin-film gain media are highly interesting as versatile, mechanically flexible, wavelength tunable active photonic devices with low-cost fabrication techniques that can fit any substrate and are useful for optical communications, sensing, and spectroscopy [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Among different options, dye-doped polymers are an attractive strategy to generate compact, flexible, and easy-to-handle solidstate organic lasers, as the small molecule active dye can be fine-tuned to fulfill all the physical requirements until reaching its best, and then the most appropriate polymeric matrix [e.g., polystyrene, PS, or poly(methyl methacrylate), PMMA] can be selected and the mixture can be optimized to achieve the desired material performances [15][16][17].…”