Study On Optical Cavities In Organic Lasers

Optical microcavity has been widely used as an important optical element in lasers,sensors,and filters due to its specific optical structure.Although studies on inorganic lasers have been more and more mature since 1960,researches on electrically pumped organic lasers are facing grand challenges and remain to be explored.Therefore,the present research focuses on fabricating organic optical microcavity and a distributed Bragg reflector?DBR?with high conductivity.The specific researches process and findings are as follows:Firstly,two ?-conjugated molecules of?E?-3-?4-?diphenylamino?phenyl?-1-?4-fluoro-2-hydroxyphenyl?prop-2-en-1-one?DFHP?and?E?-3-?4-?bis?4-methoxyphenyl?amino?phenyl?-1-?4-fluoro-2-hydroxyphenyl?prop-2-en-1-one?DFPHP?with a small difference of substituent groups were designed and synthesized.The solution-exchange method adopted,DFHP were self-assembled into amorphous microspheres while DFPHP tended to grow into crystalline rhombic microcrystals.The head of DFHP organic molecules can form hydrogen-bond with ethanol molecules and the tail of DFHP dissolve in dichloromethane?DCM?phase,which exhibits the amphiphilic nature,contributing to the self-assembly of microspheres.In contrast,both the head and the tail of DFPHP can have hydrogen-bond with the ethanol molecules,which lead to the ordered DFPHP molecular packing and then the formation of rhombic microcrystals.Furthermore,based on simulated growth/equilibrium morphology,DFHP form the amorphous microspheres other than the crystalline microcrystals due to the lower attachment energy?Etotal =-43.5 kcal/mol?as compared with that?Etotal =-53.1 kcal/mol?of DFPHP.Our demonstration can indeed build the structure-morphology relationship for rational fabrication of organic micro/nanostructures,which would contribute to a new idea to fabricate the optical cavity in micro/nano size.Secondly,according to the detailed investigation on lead halide materials,we finally chose Pb I₂ as the high refractive index part in our DBR due to its good conductivity and high refractive index.After that,by testing the optoelectronic properties of single DBR based on different combinations,Pb I₂/ Mo O₃ were found to be the best to fabricate the DBR.Meanwhile,by changing the driving source from direct current into alternating current,the DBR showed a great improvement in conductivity,whose current density could reach 1000 m A/cm2 under 3 V.Combining this new DBR with a specific OLEDs,the Vertical-Cavity-Surface-Emitting-Laser?VCSEL?like optoelectronic devices were demonstrated with very narrow electro-luminescent spectrum...