Research On Organic And Perovskite Laser Materials And Devices And Performance Optimization

Organic semiconductor laser materials have attracted wide attention due to their advantages,such as low cost,simple preparation process,tunable emission wavelength,and low threshold.At present,the research of optically pumped organic lasers has matured,but the electro-pumped organic lasers are still the challenge to be solved in the field of laser research.The main challenge in achieving organic pumped lasers is the low carrier mobility of organic semiconductor materials,the triplet accumulation,and inevitably photonic losses of device configuration.To solve this problem,the effective method is to develop new low-threshold organic laser materials,optimize the optical gain of the developed organic laser materials,screen organic luminescent materials with high carrier mobility,and optimize the optical gain performance.This article has carried out the following research according to this idea:?1?Developed two kinds of polysilicon-based pure blue organic laser materials,namely PSF-Cz and PSF-Ph.Characterize the photophysical and optical gain characteristics of two organic thin film devices,including absorption spectra,fluorescence spectra,thresholds for amplified spontaneous emission?ASE?,optical net gain,and loss.The laser characteristics of PSF-Cz were studied using a one-dimensional second-order distributed feedback?DFB?grating.The low laser threshold of 0.169?J/cm² and output slope efficiency of 4.2%were achieved at lasing,peak position 448.4 nm.Finally,based on the basic theory of F?rster energy transfer,using the host-guest doping method,the optical gain characteristics of the F8BT?yellow-green material?thin film device were optimized by blend F8BT into PSF-Ph.The optical gain characteristics of the F8BT-PSF-Ph blend films were also performed as a function of doping ratio.?2?The pure PCDTBT,which shows no laser behavior,was incorporated into the matrix of F8BT.The ASE was achieved at infrared wavelength range near by 710 nm with low threshold of21?J/cm² in F8BT-PCDTBT blends.The laser gain related properties of the blended material were characterized in detail.The effect of host-guest doping ratio on the optical gain performance of F8BT-PCDTBT blend films was investigated.The transient absorption spectra of the blended samples were studied by the Pump-Probe test system to understand the luminescence mechanism of the blends.Nanoimprint technology has been used to fabricate manufacture flexible one-dimensional DFB laser device,which achieved low threshold lasing at infrared wavelength range.Finally,another polymer,P3HT,was blended into this system to obtain ternary blends.ASE wavelength tuning from red to near infrared?IR?,i.e.,650 nm-710 nm,with optical window of 60nm was achieved.?3?The perovskite material CH₃NH₃PbI₃ was deposited on the substrate by a two-step process to prepare a thin-film device.The amplified spontaneous emission characteristics were characterized.The effects of substrate type,spin coating process and the pump wavelength on the ASE threshold of CH₃NH₃PbI₃ thin film were investigated.Finally,a perovskite thin film was prepared by incorporating PbBr₂ into PbI₂.By adjusting the ratio of iodine to bromine,wavelength tuning of nearly 140 nm in the near-infrared range were achieved...