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Condensed Matter Physics Commons

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Full-Text Articles in Condensed Matter Physics

Hyperpolarization Of Silicon Nanoparticles With Tempo Radicals, Jingzhe Hu, Nicholas Whiting, Pratip Bhattacharya Mar 2018

Hyperpolarization Of Silicon Nanoparticles With Tempo Radicals, Jingzhe Hu, Nicholas Whiting, Pratip Bhattacharya

Nicholas Whiting

Silicon-based particles can be hyperpolarized via dynamic nuclear polarization to enhance 29Si magnetic resonance signals. Application of this technique to nanoscale silicon particles has been limited because of the low signal enhancements achieved; it is hypothesized that this is due to the low number of endogenous electronic defects inherent to the particles. We introduce a method of incorporating exogenous radicals into silicon nanoparticle suspensions in order to improve the hyperpolarization of 29Si nuclear spins to levels sufficient for in vivo MR imaging. Calibration of radical concentrations and polarization times are reported for a variety of silicon particle sizes (30−200 nm …


Investigation Of Charge Transport In Organic Polymer Donor/Acceptor Photovolatic Materials, Zubair Ahmad, Shahino Mah Abdullah, Khaulah Sulaiman Apr 2014

Investigation Of Charge Transport In Organic Polymer Donor/Acceptor Photovolatic Materials, Zubair Ahmad, Shahino Mah Abdullah, Khaulah Sulaiman

Zubair Ahmad

Pi-conjugated organic semiconductors have long been used as either holes or electrons transport materials. Recently ambipolar charge carrier transport in these materials have been reported in many investigations. In this paper, we report on the basis of experimental results that the organic semiconductor (donor/acceptor) materials can be as good electrons transporters as these materials are holes transporters. In our study, the solution-processed unipolar diodes based on organic materials P3HT, VOPCPhO and their blends with PCBM have been fabricated. The I-V characteristics of these diodes have been analyzed in the space charge limited current regime. The values of the electron and …