Proceedings of International Conference on Perovskite Thin Film Photovoltaics and Perovskite Photonics and Optoelectronics (NIPHO20)
DOI: https://doi.org/10.29363/nanoge.nipho.2020.064
Publication date: 25th November 2019
During the last years, Metal Halide Perovskites (MHPs) have attracted special attention as an efficient conversion films for photovoltaics, or excellent gain media to construct optical sources. Particularly, most of the works have been focused on CH3NH3PbI3polycrystalline thin films, where stimulated emission was observed under pulsed excitation and power density thresholds as low as 1 μJ/cm2at room temperature [1,2]. More recently, laser emission under continuous wave excitation have been also demonstrated [3] and even an integrated optical amplifier-photodetector on a flexible substrate was recently reported [4].MHPs can be also synthesized as colloidal nanocrystals. In particular, CsPbX3 nanocrystals (NCs) revealed extraordinary properties for optoelectronics. In our recently published work [5], thin films of CsPbX3NCs were properly optimized to enhance the generation of photoluminescence, and with it, the optical gain. In particular, Amplified Spontaneous Emission (ASE) is demonstrated with three different compositions (X3=Br3, X3=Br1.5I1.5, X3=I3). Indeed, these films can demonstrate ASE thresholds lower than 5 μJ/cm2at cryogenic temperatures under nanosecond excitation. Finally, the physical origin of ASE is discussed and demonstrated its single exciton origin in contrast to biexcitonic, as claimed in literature. These results pave the road towards the development of an active photonics technology based on CsPbX3NCs.
Financial support from Spanish MINECO through project No. TEC2017-86102-C2-1-R, the Generalitat Valenciana via project Q-Devices (Prometeo/2018/098), and the European Research Council (ERC) via Consolidator Grant (724424 -No-LIMIT) is gratefully acknowledged. J.N.-A. acknowledges the Spanish MINECO for his Ph.D. Grant No. BES-2015-074014.