Ongoing collaborative work with Professors Daniel R. Gamelin and David S. Ginger at the University of Washington have resulted in two new publications: “Direct Measurement of Acceptor Group Localization on Donor–Acceptor Polymers Using Resonant Auger Spectroscopy” and “Ferromagnetic excited-state Mn2+ dimers in Zn1−xMnxSe quantum dots observed by time-resolved magnetophotoluminescence“.

In the first publication, Phu Nguyen performed density functional calculations to investigate the electronic structure of the LUMO of PCPDTBT and PCDTBT, two similar donor/acceptor-type polymers. These materials are of interest for application in organic photovoltaic devices.

In the second publication, Joseph May performed density functional calculations on ZnSe nanocrystals doped with Mn2+ ions to elucidated the microscopic orbital exchange interactions that give rise to ferromagnetic coupling within photoexcited Mn2+—Mn2+ dimers.

Bo Peng’s paper titled “Effects of Crystallographic and Shape Anisotropies on Dopant-Carrier Exchange Interactions in Magnetic Semiconductor Quantum Dots” is now available online in The Journal of Physical Chemistry C. This paper examines the role of nanocrystal shape and crystalline anisotropy on carrier-mediated magnetism in diluted magnetic semiconductor nanocrystals using density functional theory and analytical perturbation theory.

Congratulations to Bo Peng and Jeremy Lehner for passing the departmental second-year exam. Bo presented his work on anisotropic exchange splittings in transition-metal-doped II-VI semiconducting nanocrystals. Jeremy presented his work on geometry optimization, discussing a modification to the rational function optimization for transition state optimizations.

Joseph May and Ryan McMorris’ paper, “Ferromagnetism in p-Type Manganese-Doped ZnO Quantum Dots”, which describes how nitrogen dopants affect the magnetic ordering of manganese unpaired spins in zinc oxide quantum dots, was just accepted into the Journal of Physical Chemistry Letters. The “Just Accepted Manuscript” is available here.

Bo Peng’s paper, “Theoretical Evaluation of Spin-Dependent Auger De-Excitation in Mn2+-Doped Semiconductor Nanocrystals,” which describes Auger de-excitation process in Mn2+-doped CdS quantum dots, was just accepted into the Journal of Physical Chemistry C. The “Just Accepted Manuscript” is available here.