We demonstrate the working of organic-inorganic hybrid light emitting diodes using cadmium sulphide nanoparticles doped in light emitting polymers. Cadmium sulphide nanoparticles were prepared by precipitation technique and doped in active light emitting polymers. We used blue emitting polymer PFO and green emitting polymer F8BT as active polymers. The j-L-V curves of nanoparticles based devices were compared with polymer only standard devices. Our results show enhanced performance such as increased conductivity and higher luminance, when nanoparticle are incorporated into the device.
Deoxyribonucleic acid lipid complex thin films are used as a host material for laser dyes. We tested PicoGreen dye, which is commonly used for the quantification of single and double stranded DNA, for its applicability as lasing medium. PicoGreen dye exhibits enhanced fluorescence on intercalation with DNA. This enormous fluorescence emission is amplified in a planar microcavity to achieve yellow lasing. Here the role of DNA is not only a host medium, but also as a fluorescence dequencher. With the obtained results we have ample reasons to propose PicoGreen dye as a lasing medium, which can lead to the development of DNA based bio-lasers.
Biopolymer light emitting diodes were fabricated by using all solution processable polymers incorporating biomaterials such as deoxyribonucleic acid lipid complex as an electron blocking layer. Light emission is from a blend of fluorene based copolymers. The devices with electron blocking layer exhibited higher brightness and luminous efficiency. The increased luminance of the multilayer polymer LED is attributed to the contribution from DNA:CTMA as electron blocking layer and PFN, a derivative of polyfluorene, as electron injection layer. Our results show four fold increase in luminance values when DNA is used as electron blocking layer.
Chalcogenide glasses are amorphous semiconductors with a number of interesting properties required for photonic
devices. Particularly, their optical properties can be tuned through the change of the glass composition. We investigate
second-order nonlinear optical properties of chalcogenide glass (Ge27Se64Sb9) thin films fabricated by thermal
evaporation. The strong second-harmonic generation observed for the samples investigated is analyzed as a function of
incident polarization. Furthermore, the role of multipole effects in second-harmonic generation is also studied by using
two beams at the fundamental frequency. Our results suggest that the higher-multipole effects are present and contribute
significantly to the second-harmonic response of chalcogenide the samples.