ABSTRACT
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.
ABSTRACT
For the first time, large-area, flexible organic-inorganic tin perovskite solar modules are fabricated by means of an industry-compatible and scalable blade-coating technique. An 8-cell interconnected mini module with dimensions of 25 cm2 (active area = 8 × 1.5 cm2) reached 5.7% power conversion efficiency under 1000 W/m2 (AM 1.5G) and 9.4% under 2000 lx (white-LED).
ABSTRACT
Thin-film organic-inorganic hybrid perovskite (MeNH3PbI3) solar cells have displayed remarkably high photoconversion efficiencies, making their net-shaping as flexible device elements desirable for a number of applications. Simulations show greatly enhanced light absorption in perovskite fibers in comparison to their thin-film counterparts, which demand the processing of hybrid perovskites in the one-dimensional morphology. We report here on the single-step fabrication of MeNH3PbI3 nanofibers on a customized electrospinning process performed under inert conditions. Our results demonstrate reproducible synthesis of electrospun fiber mats in which the fiber dimensions were tailored by adjusting the polymer (PVP) content. Photoluminescence studies on the perovskite fibers revealed a blue shift of the emission peak possibly due to strain or charge confinement effects. The hybrid perovskite nanofibers offer promising applications in flexible and stretchable optoelectronics.