Welcome to Zhigang Shuai Group !
Zhigang Shuai 帅志刚
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Office: S511, Meng Min Wei SciTech Building (蒙民伟科技大楼南楼511) Department of Chemistry Tel:+86-10-62797689 Researcher ID:H-5576-2011(H-index 79) |
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Honours and Awards
Journal Editorials
Services
Recent Selected papers
Please visit the web page Publications for the full list. |
Developing and applying new theoretical and computational methods
to study optoelectronic functional materials
The research in the Shuai Group involves theoretical and computational studies of phenomena in organic and polymeric functional materials.
A primary goal is to develop and apply new computational methods to explain and predict the opto-electronic functions of organic functional materials. For instance, we are interested in the charge/thermoelectric transports in organic semiconductors and carbon nano-ribbon and sheets, electronic excited state decay processes relevant to organic light-emitting quantum efficiency and spectrum, charge and exciton dynamics in polymer photovoltaics, thermoelectric figure of merits, nonlinear optical responses and multiphoton absorption, supramolecular self-assembly and disassembly.
These also include methods for correlated electron such as quantum chemistry density matrix renormalization group and equation of motion coupled cluster theory, both at semiempirical levels.
2021 News
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2021/09/24 |
Congratulations to Dr Yu Wang for her new paper has been published in Materials Horizons! Phosphorescent organic light-emitting diodes (PhOLEDs) are leading candidates for displays or lighting technologies. Recently, blue phosphorescent tetradentate Pt(II) complexes have been attracting extensive attention due to their high phosphorescence quantum efficiency and numerous chemical structures on account of flexible ligand frames and modifications. Using quantum chemistry coupled with our thermal vibration correlation function (TVCF) formalism, we investigated the triplet excited state energy surface and the decay processes involving both direct vibrational relaxation and minimum energy crossing point (MECP) via the transition state (3TS) to the ground state (S0) for 16 recently experimentally reported blue-emitting tetradentate Pt(II) emitters containing fused 5/6/6 metallocycles. We found that (i) in most cases, the direct vibrational relaxation deactivations dominated the triplet non-radiative decay because either the 3TS is too high or the MECP is not reachable. Hence, results from the TVCF formalism agreed well with the experiments for the phosphorescence quantum efficiency; (ii) only when both 3TS and MECP are low, for instance, for PtON1-oMe, deactivations via MECP dominated the triplet non-radiative decay. |
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2021/09/23 |
Congratulations to Tong Jiang for his new paper has been published in J. Phys. Chem. Lett.! We propose a method to calculate the spectral functions of many-body systems by Chebyshev expansion in the framework of matrix product states coupled with canonical orthogonalization (coCheMPS). The canonical orthogonalization can improve the accuracy and efficiency significantly because the orthogonalized Chebyshev vectors can provide an ideal basis for constructing the effective Hamiltonian in which the exact recurrence relation can be retained. In addition, not only the spectral function but also the excited states and eigenenergies can be directly calculated, which is usually impossible for other MPS-based methods such as time-dependent formalism or correction vector. The remarkable accuracy and efficiency of coCheMPS over other methods are demonstrated by calculating the spectral functions of spin chain and ab initio hydrogen chain. For the first time we demonstrate that Chebyshev MPS can be used to deal with ab initio electronic Hamiltonian effectively. We emphasize the strength of coCheMPS to calculate the low excited states of systems with sparse discrete spectrum. We also caution the application for electron-phonon systems with dense density of states. |
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2021/07/19
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Congratulations to Qi Sun for her new paper has been published in Nano Letters! Luminescence in molecular aggregates can be quenched either by intermolecular charge transfer or by forming a dipole-forbidden lower Frenkel exciton in H-aggregate. Taking intermolecular charge transfer and excitonic coupling into a threestate model through localized diabatization, we demonstrate that the low-lying intermolecular charge-transfer state could couple with the upper bright Frenkel exciton to form dipole-allowed S1 that lies below the dark state, which accounts for the recent experimentally discovered strong luminescence in organic light-emitting transistors (OLETs) system with DPA and dNaAnt herringbone aggregates. The condition of forming such bright state is that the electron and hole transfer integrals, te and th, are of the same sign, and should be notably larger than the excitonic coupling (J), that is , te × th > 2J2. This theoretical finding not only rationalizes recent experiments but unravels an exciting scenario where strong luminescence and high charge mobilities become compatible, which is a preferable condition for both OLETs and electrically pumped lasing. |
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2021/07/17
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Congratulations to Weitang Li for his new paper has been published in Nature Communications!
The nonlocal electron-phonon couplings in organic semiconductors responsible for the fluctuation of intermolecular transfer integrals has been the center of interest recently. Several irreconcilable scenarios coexist
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