Study On Lead Iodide Perovskite Nanoplatelets Lasers With Low Lasing Thresholds

Organic-inorganic hybridized perovskite,which is an excellent semiconductor material and a promising laser gain medium due to the characteristics of long carrier diffusion length,high luminous efficiency,etc.,has attracted widespread attention in many fields such as photovoltaics,laser,and so on.And the natural boundary of the single crystalline perovskite nanoplatelets provides a perfect resonant cavity for lasing,helping to achieve population inversion.In addition,the band gap of the perovskite material is tunable and can produce laser from near infrared to ultraviolet.In short,perovskite materials have bright application prospects in the field of lasers,and they are expected to bring new opportunities for nanophotonics,chemical-biosensing,and optical computing.The focus of this project is to start from the perfect whispering-gallery mode resonant cavity formed by the organic-inorganic hybrid single crystal perovskite,and to combine perovskite materials with controllable synthesis and excellent optical properties,to develop perovskite materials in nanolasers field research.In the experiment,a single crystalline lead iodide nanoplatelets with regular shape and size(5?m~120?m)was prepared by vapor deposition method and used as a template by adjust different evaporation conditions(deposition time,tube furnace temperature,the flow rate,sample placement and so on)successfully synthesized high-quality,low-defect single crystalline lead iodide perovskite nanoplatelets,providing a perfect resonant cavity for the realization of nanolasers.Meanwhile,at room temperature,we studied the lasing performance of the synthesized single crystalline perovskite nanoplatelets using a home-made microfocus system.The effects of different purity of lead iodide and different size single crystal perovskite nanoplatelets on lasing properties were explored.It was found that increasing the purity of lead iodide can reduce the lasing threshold and the full width at half-maximum(FWHM)of perovskite nanoplatelets.And the peak position of the lasing spectrum appeared redshift with the increase of the size of the nanoplatelets,the peak spacing gradually decreased with the increase of the size of the nanoplatelets.In the experiment,we successfully achieved a lower threshold,high quality factor Q single crystalline perovskite nanoplatelets lasers with a threshold of 18.87?J/cm~2 and the quality factor Q of 2164 using a high-quality,low-defect perovskite nanoplatelets.The laser performance of the prepared perovskite nanoplatelets has been significantly higher than that of similar nanolasers reported in the literature.