Study On The Optical Properties Of Several Optical Information Materials

There are many kinds of optoelectronic information materials,which can be mainly divided into two categories according to the composition: organic materials and inorganic materials.The application of the optoelectronic information materials is much extensive such in lighting,power source and light modulation,which have made excellent performances in our lives.In this paper,we choose several representative research objects and hot problems in the field of optoelectronic information material to study by using the multi-spectroscopic system in our research group.Through the research,we hope to deepen people’s knowledge and understanding of optoelectronic information materials,finding a new application for optoelectronic information materials,and open up a new application direction.The main results of the study are as follows:(1)The spectral and structural properties of three organic oligomers,F-P,F-P-F and P-F-P-F-P,with fluorene and phenothiazine units were studied,and they are organic optoelectronic materials with repeating conjugated structural units.By quantum chemical calculation,luminescence dynamics,nonlinear optics,the physical connection between molecular structure and spectral properties has been discussed in detail.As a result,quantum chemical calculations show that with the increase of the conjugate element,the HOMO(highest occupied molecular orbital)of molecules increases gradually and LUMO(lowest unoccupied molecular orbital)decreases gradually,simultaneously the band gap becomes narrower.This result was in agreement with the experimental results of steady-state absorption and emission spectra;the luminescence kinetics showed that the luminescence lifetime of the molecule also increased with the increase of the repeating unit.The luminous performance has further improved.This tendency is consistent with the results of steady-state luminescence intensity.In addition,based on the application of Z-scan technology,we found that the two-photon absorption cross section of the molecule also increases with the increase of the conjugated unit.The experimental results show that adding conjugated elements would be an effective way to improve the optical properties of optoelectronic information materials.(2)We investigated the ultrafast photo-physical properties of a red light organic optoelectronic material TPA-DCPP,which is composed of a conjugated unit,an electron donor and an electron acceptor structure.In view of its special molecular structure,we first compared it in three different solvents in toluene,CHCl3 and THF to study its ultrafast photo-physical process,and discuss the effect of solvent polarity on its photo-physical properties.The results show that TPA-DCPP has obvious intramolecular charge transfer in toluene.After the photoexcitation,the transfer rate from the initial excited state to the intramolecular charge-transfer state gradually increases with the polarity of the solvent,when TPA-DCPP is dissolved in the THF with high polarity,the corresponding charge-transfer state would be superimposed with the initial excited state.Based on the time related single photon counting technology,the luminescence kinetics of TPA-DCPP showed that the luminescence lifetime of TPA-DCPP gradually accelerated with the increase of solvent polarity.And then,we studied the photoluminescence characteristics of TPA-DCPP in toluene,the results show that the excited state of TPA-DCPP is much sensitive to the solvent polarity.From the temperature dependent luminescence intensity,it is found that the luminescence intensity gradually increases,the luminescence peak blue shifts,the luminescence bandwidth becomes narrow,when the temperature.Considering the previous discussion of the relaxation path,the emission photon of molecule should be originated from the intramolecular-charge-transfer state rather than the initial excited state.(3)Besides the organic optoelectronic materials,inorganic nanoparticles are also an important class of optoelectronic information materials.We chose the Zn Cu In S/Zn S core-shell quantum dots synthesized in the research group,and discussed the optical properties of this kind of green nanoparticles,so as to analyze the photoluminescence properties of Zn Cu In S quantum dots of Zn S shells with different thicknesses and the regulation mechanism of the core-shell,by employing the luminescence kinetics and the temperature dependent photoluminescence spectra.The results show that the core-shell can inhibit the surface defect state and electron-lattice interaction of the nucleus,which would reduce the non-radiative relaxation path.Moreover,the temperature dependent photoluminescence data confirm that the increase of core-shell thickness will increase the activation energy of the quantum dots.These results enriched the knowledge and understanding of the luminous properties of such core-shell quantum dots.(4)In addition to the optoelectronic information luminescent materials as mentioned above,photonic crystal is a kind of novel optical material.;It could not emite photon,but its unique periodic structure can effectively modulate the light wave.The azo material is a kind of traditional birefringent material,which can change the polarization characteristic of light under light conditions.We try to combine these two unique optical materials to discuss the mechanism of photonic crystal on the birefringence effect.Therefore,we prepared opal photonic crystals with different photonic bandgap based on polymethyl methacrylate(PMMA).Meanwhile,the Azo thin films were combined to construct photonic crystal azo system.The photon crystal bandgap and film thickness were analyzed to control the photoreaction rate.The results show that the photo-chromatic birefringence of the three-dimensional opal crystals is enhanced by the light regulation of the internal network microporous structure.The azo-dye doped polymer has better optical and physical properties than the pure azo film,moreover photonic crystals can help the azo film to further modulate the polarization of light wave and improve the effect of photo-induced birefringence.These results provide experimental basis for the further development of photonic crystal function.