RESUMO
The development of random lasing (RL) with predictable and controlled properties is an important step to make these cheap optical sources stable and reliable. However, the design of tailored RL characteristics (emission energy, threshold, number of modes) is only obtained with complex photonic structures, while the simplest optical configurations able to tune the RL are still a challenge. This work demonstrates the tuning of the RL characteristics in spin-coated and inkjet-printed tin-based perovskites integrated into a vertical cavity with low quality factor. When the cavity mode is resonant with the photoluminescence (PL) peak energy, standard vertical lasing is observed. More importantly, single mode RL operation with the lowest threshold and a quality factor as high as 1 000 (twenty times the quality factor of the resonator) is obtained if the cavity mode lies above the PL peak energy due to higher gain. These results can have important technological implications toward the development of low-cost RL sources without chaotic behavior.
RESUMO
Manipulation of the exciton emission rate in nanocrystals of lead halide perovskites (LHPs) was demonstrated by means of coupling of excitons with a hyperbolic metamaterial (HMM) consisting of alternating thin metal (Ag) and dielectric (LiF) layers. Such a coupling is found to induce an increase of the exciton radiative recombination rate by more than a factor of three due to the Purcell effect when the distance between the quantum emitter and HMM is nominally as small as 10 nm, which coincides well with the results of our theoretical analysis. Besides, an effect of the coupling-induced long wavelength shift of the exciton emission spectrum is detected and modeled. These results can be of interest for quantum information applications of single emitters on the basis of perovskite nanocrystals with high photon emission rates.