Contact Information
MIT Department of Chemistry
Room 6-230
Cambridge, MA 02139
mit.edu email: tyzhu
Year joined: 2013
Google Scholar profile
Education
| 2013 | BS in Chemical Physics | University of Science and Technology of China | Advisor: Kaifu Luo |
Research Interests
Many Pair Expansion
Density functional theory (DFT) has obtained much progress in its formulations and applications today, but still suffers from several weaknesses. Common density functionals have self-interaction errors (also called delocalization errors), and are unable to describe the strong correlations and dispersion interactions. We propose the Many Pair Expansion (MPE) in DFT, which is a hierarchy that systematically corrects any deficiencies of an approximate functional to finally converge to the exact energy. The density of a system is decomposed into localized and nodeless two-electron densities, which are then used to construct four-, six-electron densities. Numerically exact results for these few particle densities can then be used to correct an approximate density functional via any of several of many-body expansions. We have applied this method to several important lattice models (Hubbard, Peierls-Hubbard, PPP) and obtained very promising results. Now we are implementing MPE on ab initio Hamiltonians and evaluating its performance for real molecules.
OLED Host-Guest Simulation
The host-guest systems are the most crucial component in an organic light-emitting diode (OLED) device. Much research in this field focuses on searching for highly efficient OLED emitters (guests). However, the host-guest interaction also plays a significant role in achieving high electroluminescence efficiency. I am now using QM/MM simulations to investigate the host-guest interactions inside a phosphorescent OLED device. We are mainly studying the possible charge transfer and energy transfer routes in these systems and trying to understand the charge recombination mechanisms. This work can help design better host-guest combinations and improve the efficiency for OLED devices.