Study On Amplified Spontaneous Emission And Performance Of Novel Organic Semiconductors

Organic semiconductor lasers(OSLs)are well known for their many advantages such as low-cost fabrication,broadly tunable spectral window,compact system,potential flexibility,and easy integration with other optoelectronic devices,which have huge application potential in the optoelectronic industry.Especially ?-conjugated organic semiconductor materials have been widely explored in various optoelectronic applications,such as organic light-emitting diodes(OLEDs),organic solar cells(OPVs),organic thin film transistors(OTFTs)and organic semiconductor lasers(OSLs),etc.However,various organic light-emitting laser devices have demonstrated the characteristics of spontaneous radiation amplification by optically pumping a solid-state thin film,electrically-pumped organic laser devices have not yet been realized.The current research in this field is mainly divided into two aspects: organic material design and device structure.The main work of this paper is based on new organic laser materials and OLED structures.The high-performance,newly developed spirochrome trapezoidal material was characterized and tested in detail;the material of spirochrome trapezoidal and polyfluorene material were compared and characterized under the OLED structure;the optical pumped OLED laser was studied;and finally the doping system was used to studies the application prospect of triplet exciton traps in organic lasers and provides a new possibility for the realization of electric pumped OLED lasers.(1)Compared with Poly(9,9-dioctylfluorene)(PFO),the basic photophysical properties and amplified spontaneous emission threshold test of spiro-fused ladder-type oligophenylenes,named as SpL(2)-1 and SpL-1 were studied,and the low temperature PL and PLE spectra of the three materials were tested.We performed a detailed study of ASE performance,and we tested the ASE of three materials at different excitation wavelengths,systematically studied the ASE behavior of materials at different wavelengths,and explored the correlation between ASE behavior and the absorption coefficient of the material.The ASE test was carried out at a specific wavelength with high pump energy.It was found that there was a phenomenon that the FHWM spectrum was particularly narrowed.(2)A detailed comparative study of SpL(2)-1 and PFO was performed based on the OLED structure.The ASE behaviors on ITO substrates,ITO/ZnO substrates,and complete OLEDs were studied separately.On the ITO substrate,we tested the ASE threshold and the net gain coefficient,and found that the ITO electrode annihilation of the organic gain medium is very serious;and then ASE characterization of the two materials on the ITO/ZnO substrate,and through regulation The thickness of the metal oxide ZnO,the laser behavior of PFO and SpL(2)-1 have been greatly restored,and it can be seen that ZnO can effectively block the influence of ITO on the organic gain medium and can well limit the optical waveguide mode in luminescence layer.Finally,we realized the two kinds of material optical pumped OLED lasers in the complete OLED structure.Through comparison,it was found that the spiro-trapezoidal structure material with high gain coefficient can achieve better performance in OLED devices,and it is possible to realize the organic laser of electric pumped.(3)we present a novel concept to construct triplet-singlet guest-host gain systems with incorporating iridium complexes as the triplet harvesters and a fluorescent conjugated polymer as the gain media to achieve light amplification.The pumping energy is absorbed by the triplet phosphorescent complex,and the triplet excitons are collectively captured by the F?rster energy transfer to the fluorescence gain medium,and the laser is emitted using the self-excited radiation of the fluorescence gain medium and the captured triplet exciton energy.We performed a ternary blending systems,performed detailed ratio doping and testing,and the experimental results show that the triplet-single-state host-guest gain system can successfully amplify light with a lower ASE threshold.