This review encompasses properties and applications of polycrystalline or amorphous, Transparent Conducting Oxides (TCO) semiconductors. Coexistence of electrical conductivity and optical transparency in TCO depends on the nature, number and atomic arrangements of metal cations in oxides, on the resident morphology and presence of intrinsic or introduced defects. Therefore, TCO semiconductors that are impurity-doped as well as the ternary compounds and multi-component oxides consisting of combinations are discussed. Expanding use of TCO is endangered by scarcity, cost of In, fragility of glass, limited transparency to visible light, instability above >200 °C, non-flexible for application of flexible solar cell; thus driving search for alternatives such as graphene or CNT, that are more stable under acidic, alkaline, oxidizing, reducing and elevated temperature. There are reasons to conclude that there is need to develop large area deposition techniques to produce TCO films with high deposition rate. TCOs are mostly n-type semiconductors, but p-type are also being researched

Direct white light emission from ultrasmall europium nanocrystals (WLEuNCs) is reported in the present study. The one-pot synthesis of WLEuNCs was done using thiourea, oleyl amine (OlAm), oleyl alcohol (OA), and Eu (III) oxide at 120 °C. Upon excitation at 250 nm, three emission peaks at 318, 429 (broad peak covering green spectrum of light), and 618 nm were observed. The combination of these blue, green, and red emissions resulted in white light emission from the europium nanocrystals. The CIE coordinates (0.26, 0.32) confirm near white light emission with a quantum yield of ∼7%. The role of thiourea was found to be indispensable in emission of white light from nanocrystals. As per Commission Internationale de L'Eclairage (CIE) coordinates, as synthesized nanocrystals exhibited a slight "bluing effect". This effect was rectified by cooling the solution to 3−4 °C. Upon cooling, there was substantial improvement in white light emission (CIE coordinates 0.34, 0.30) along with a slight enhancement in quantum yield (∼10%). The white light emission might also be due a wide band gap of 3.7 eV.

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Neurotransmitters have been of immense scientific interests for their importance as human-health biomarkers. Several reports suggest required improvisations in sensing capabilities of these neurotransmitters. Here authors report novel synthesis methodology...

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