Category Archives: Semiconductors

Analysis of Molecular Orientation in Organic Semiconducting Thin Films Using Static Dynamic Nuclear Polarization Enhanced Solid-State NMR Spectroscopy #DNPNMR

Suzuki, K., et al., Analysis of Molecular Orientation in Organic Semiconducting Thin Films Using Static Dynamic Nuclear Polarization Enhanced Solid-State NMR Spectroscopy. Angew. Chem. Int. Ed., 2017. 56(47): p. 14842-14846.

https://www.ncbi.nlm.nih.gov/pubmed/28994190

Molecular orientation in amorphous organic semiconducting thin-film devices is an important issue affecting device performance. However, to date it has not been possible to analyze the “distribution” of the orientations. Although solid-state NMR (ssNMR) spectroscopy can provide information on the “distribution” of molecular orientations, the technique is limited because of the small amount of sample in the device and the low sensitivity of ssNMR. Here, we report the first application of dynamic nuclear polarization enhanced ssNMR (DNP-ssNMR) spectroscopy for the orientational analysis of amorphous phenyldi(pyren-1-yl)phosphine oxide (POPy2 ). The (31) P DNP-ssNMR spectra exhibited a sufficient signal-to-noise ratio to quantify the distribution of molecular orientations in amorphous films: the P=O axis of the vacuum-deposited and drop-cast POPy2 shows anisotropic and isotropic distribution, respectively. The different molecular orientations reflect the molecular origin of the different charge transport behaviors.

Scalable Spin Amplification with a Gain Over a Hundred

Negoro, M., et al., Scalable Spin Amplification with a Gain Over a Hundred. Phys. Rev. Lett., 2011. 107(5): p. 050503.

http://link.aps.org/doi/10.1103/PhysRevLett.107.050503

We propose a scalable and practical implementation of spin amplification which does not require individual addressing nor a specially tailored spin network. We have demonstrated a gain of 140 in a solid-state nuclear spin system of which the spin polarization has been increased to 0.12 using dynamic nuclear polarization with photoexcited triplet electron spins. Spin amplification scalable to a higher gain opens the door to the single spin measurement for a readout of quantum computers as well as practical applications of nuclear magnetic resonance spectroscopy to infinitesimal samples which have been concealed by thermal noise.

Scalable Spin Amplification with a Gain Over a Hundred

Negoro, M., et al., Scalable Spin Amplification with a Gain Over a Hundred. Phys. Rev. Lett., 2011. 107(5): p. 050503.

http://link.aps.org/doi/10.1103/PhysRevLett.107.050503

We propose a scalable and practical implementation of spin amplification which does not require individual addressing nor a specially tailored spin network. We have demonstrated a gain of 140 in a solid-state nuclear spin system of which the spin polarization has been increased to 0.12 using dynamic nuclear polarization with photoexcited triplet electron spins. Spin amplification scalable to a higher gain opens the door to the single spin measurement for a readout of quantum computers as well as practical applications of nuclear magnetic resonance spectroscopy to infinitesimal samples which have been concealed by thermal noise.

Optically Erasing Disorder in Semiconductor Microcavities with Dynamic Nuclear Polarization

Liew, T.C.H. and V. Savona, Optically Erasing Disorder in Semiconductor Microcavities with Dynamic Nuclear Polarization. Phys. Rev. Lett., 2011. 106(14): p. 146404.

http://link.aps.org/doi/10.1103/PhysRevLett.106.146404

The mean squared value of the photonic disorder is found to be reduced by a factor of 100 in a typical GaAs based microcavity when exposed to a circularly polarized continuous wave optical pump without any special spatial patterning. Resonant excitation of the cavity mode excites a spatially nonuniform distribution of spin-polarized electrons, which depends on the photonic disorder profile. Electrons transfer spin to nuclei via the hyperfine contact interaction, inducing a long-living Overhauser magnetic field able to modify the potential of exciton polaritons.

Optically Erasing Disorder in Semiconductor Microcavities with Dynamic Nuclear Polarization

Liew, T.C.H. and V. Savona, Optically Erasing Disorder in Semiconductor Microcavities with Dynamic Nuclear Polarization. Phys. Rev. Lett., 2011. 106(14): p. 146404.

http://link.aps.org/doi/10.1103/PhysRevLett.106.146404

The mean squared value of the photonic disorder is found to be reduced by a factor of 100 in a typical GaAs based microcavity when exposed to a circularly polarized continuous wave optical pump without any special spatial patterning. Resonant excitation of the cavity mode excites a spatially nonuniform distribution of spin-polarized electrons, which depends on the photonic disorder profile. Electrons transfer spin to nuclei via the hyperfine contact interaction, inducing a long-living Overhauser magnetic field able to modify the potential of exciton polaritons.

Have a question?

If you have questions about our instrumentation or how we can help you, please contact us.