Nanoscopic mechanisms of singlet fission in amorphous molecular solid

Fission of a spin-singlet exciton into two triplet excitons, if realized in disordered organic solid, could revolutionize low-cost fabrication of efficient solar cells. Here, a divide-conquer-recombine approach involving nonadiabatic quantum molecular dynamics and kinetic Monte Carlo simulations identifies the key molecular geometry and exciton-flow-network topology for singlet-fission “hot spots” in amorphous diphenyl tetracene, where fission occurs preferentially. The simulation reveals the molecular origin of experimentally observed two time scales in exciton population dynamics and may pave a way to nanostructural design of efficient solar cells from first principles.

[1]  Paul M Zimmerman,et al.  Mechanism for singlet fission in pentacene and tetracene: from single exciton to two triplets. , 2011, Journal of the American Chemical Society.

[2]  Walter R. Duncan,et al.  Trajectory surface hopping in the time-dependent Kohn-Sham approach for electron-nuclear dynamics. , 2005, Physical review letters.

[3]  O. Sugino,et al.  Nonadiabatic couplings from time-dependent density functional theory: formulation in the Casida formalism and practical scheme within modified linear response. , 2007, The Journal of chemical physics.

[4]  Stephen R. Forrest,et al.  Ideal Diode Equation for Organic Heterojunctions. I. Derivation and Application , 2010 .

[5]  Rajiv K. Kalia,et al.  Large nonadiabatic quantum molecular dynamics simulations on parallel computers , 2013, Comput. Phys. Commun..

[6]  Xiaojing Wang,et al.  Photocatalytic oxidation dynamics of acetone on TiO2: tight-binding quantum chemical molecular dynamics study , 2005 .

[7]  J. Tully.  Molecular dynamics with electronic transitions , 1990 .

[8]  Lin-wang Wang,et al.  Overlapping fragments method for electronic structure calculation of large systems. , 2010, The Journal of chemical physics.

[9]  Flip Korn,et al.  Influence sets based on reverse nearest neighbor queries , 2000, SIGMOD 2000.

[10]  A. Nakano,et al.  Molecular control of photoexcited charge transfer and recombination at a quaterthiophene/zinc oxide interface , 2012 .

[11]  H. Ågren,et al.  Impact Ionization and Auger Recombination Rates in Semiconductor Quantum Dots , 2010 .

[12]  Nakano,et al.  Electron transport in disordered systems: A nonequilibrium quantum-molecular-dynamics approach. , 1991, Physical review. B, Condensed matter.

[13]  M. E. Casida.  Time-Dependent Density Functional Response Theory for Molecules , 1995 .

[14]  Jenny Clark,et al.  Ultrafast dynamics of exciton fission in polycrystalline pentacene. , 2011, Journal of the American Chemical Society.

[15]  D. Bowler,et al.  O(N) methods in electronic structure calculations. , 2011, Reports on progress in physics. Physical Society.

[16]  Andrew L. Ferguson,et al.  Systematic determination of order parameters for chain dynamics using diffusion maps , 2010, Proceedings of the National Academy of Sciences.

[17]  K. Hirao,et al.  A long-range-corrected time-dependent density functional theory. , 2004, The Journal of chemical physics.

[18]  E. Kaxiras,et al.  Natural dyes adsorbed on TiO2 nanowire for photovoltaic applications: enhanced light absorption and ultrafast electron injection. , 2008, Nano letters.

[19]  Paul M Zimmerman,et al.  Singlet fission in pentacene through multi-exciton quantum states. , 2010, Nature chemistry.

[20]  Priya J. Jadhav,et al.  Singlet exciton fission in nanostructured organic solar cells. , 2011, Nano letters.

[21]  G. Lu,et al.  First-principles simulations of exciton diffusion in organic semiconductors , 2011 .

[22]  A. Nakano,et al.  Divide-and-conquer density functional theory on hierarchical real-space grids: Parallel implementation and applications , 2008 .

[23]  L. Kaake,et al.  Observing the Multiexciton State in Singlet Fission and Ensuing Ultrafast Multielectron Transfer , 2011, Science.

[24]  Matthew T. Whited,et al.  Efficient singlet fission discovered in a disordered acene film. , 2012, Journal of the American Chemical Society.

[25]  W. H. Weinberg,et al.  Theoretical foundations of dynamical Monte Carlo simulations , 1991 .

[26]  Vincenzo Barone,et al.  Recent Advances in Density Functional Methods Part III , 2002 .

[27]  I. Tavernelli,et al.  Trajectory surface hopping within linear response time-dependent density-functional theory. , 2007, Physical review letters.

[28]  Mark A Ratner,et al.  Singlet exciton fission for solar cell applications: energy aspects of interchromophore coupling. , 2010, The journal of physical chemistry. B.

[29]  Yang,et al.  Direct calculation of electron density in density-functional theory. , 1991, Physical review letters.