8 research outputs found
Highly Efficient Solar Cells Based on the Copolymer of Benzodithiophene and Thienopyrroledione with Solvent Annealing
Highly efficient PBDTTPD-based photovoltaic devices with
the configuration
of ITO/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS)/PBDTTPD:
methanofullerene (6,6)-phenyl-C<sub>61</sub>-butyric acid methyl ester
(PC<sub>61</sub>BM) (weight ratio being from 1:1 to 1:4)/LiF (5 Å)/Al
(100 nm), were realized with ortho-dichlorobenzene (DCB) solvent annealing
treatment. It was revealed that the best photovoltaic device was obtained
when the blend ratio of PBDTTPD:PC<sub>61</sub>BM was modulated to
be 1:2 and processed with DCB solvent annealing for 12 h. The short-circuit
current density (<i>J</i><sub>sc</sub>) and power conversion
efficiency (PCE) values were measured to be 10.52 mA/cm<sup>2</sup> and 4.99% respectively, which were both higher than the counterparts
treated with chlorobenzene (CB) solvent annealing or the thermal annealing.
Atomic force microscopy measurements of the active layer after solvent
annealing treatment were also carried out. The phase separation length
scale of the PBDTTPD:PC<sub>61</sub>BM(1:2) layer was comparable to
the exciton diffusion length when the active layer was treated under
DCB solvent annealing, which facilitated effective exciton dissociation
and carrier diffusion in the active layer. Therefore, highly efficient
PBDTTPD-based photovoltaic devices could be achieved with DCB solvent
annealing, which indicated that solvent annealing with proper solvent
might be an easily processed, low-cost, and room-temperature alternative
to thermal annealing for polymer solar cells
The BEST framework for the search for the QCD critical point and the chiral magnetic effect
International audienceThe Beam Energy Scan Theory (BEST) Collaboration was formed with the goal of providing a theoretical framework for analyzing data from the Beam Energy Scan (BES) program at the relativistic heavy ion collider (RHIC) at Brookhaven National Laboratory. The physics goal of the BES program is the search for a conjectured QCD critical point as well as for manifestations of the chiral magnetic effect. We describe progress that has been made over the previous five years. This includes studies of the equation of state and equilibrium susceptibilities, the development of suitable initial state models, progress in constructing a hydrodynamic framework that includes fluctuations and anomalous transport effects, as well as the development of freezeout prescriptions and hadronic transport models. Finally, we address the challenge of integrating these components into a complete analysis framework. This document describes the collective effort of the BEST Collaboration and its collaborators around the world
Dense Nuclear Matter Equation of State from Heavy-Ion Collisions
The nuclear equation of state (EOS) is at the center of numerous theoretical
and experimental efforts in nuclear physics. With advances in microscopic
theories for nuclear interactions, the availability of experiments probing
nuclear matter under conditions not reached before, endeavors to develop
sophisticated and reliable transport simulations to interpret these
experiments, and the advent of multi-messenger astronomy, the next decade will
bring new opportunities for determining the nuclear matter EOS, elucidating its
dependence on density, temperature, and isospin asymmetry. Among controlled
terrestrial experiments, collisions of heavy nuclei at intermediate beam
energies (from a few tens of MeV/nucleon to about 25 GeV/nucleon in the
fixed-target frame) probe the widest ranges of baryon density and temperature,
enabling studies of nuclear matter from a few tenths to about 5 times the
nuclear saturation density and for temperatures from a few to well above a
hundred MeV, respectively. Collisions of neutron-rich isotopes further bring
the opportunity to probe effects due to the isospin asymmetry. However,
capitalizing on the enormous scientific effort aimed at uncovering the dense
nuclear matter EOS, both at RHIC and at FRIB as well as at other international
facilities, depends on the continued development of state-of-the-art hadronic
transport simulations. This white paper highlights the role that heavy-ion
collision experiments and hadronic transport simulations play in understanding
strong interactions in dense nuclear matter, with an emphasis on how these
efforts can be used together with microscopic approaches and neutron star
studies to uncover the nuclear EOS
Dense nuclear matter equation of state from heavy-ion collisions
International audienceThe nuclear equation of state (EOS) is at the center of numerous theoretical and experimental efforts in nuclear physics. With advances in microscopic theories for nuclear interactions, the availability of experiments probing nuclear matter under conditions not reached before, endeavors to develop sophisticated and reliable transport simulations to interpret these experiments, and the advent of multi-messenger astronomy, the next decade will bring new opportunities for determining the nuclear matter EOS, elucidating its dependence on density, temperature, and isospin asymmetry. Among controlled terrestrial experiments, collisions of heavy nuclei at intermediate beam energies (from a few tens of MeV/nucleon to about 25 GeV/nucleon in the fixed-target frame) probe the widest ranges of baryon density and temperature, enabling studies of nuclear matter from a few tenths to about 5 times the nuclear saturation density and for temperatures from a few to well above a hundred MeV, respectively. Collisions of neutron-rich isotopes further bring the opportunity to probe effects due to the isospin asymmetry. However, capitalizing on the enormous scientific effort aimed at uncovering the dense nuclear matter EOS, both at RHIC and at FRIB as well as at other international facilities, depends on the continued development of state-of-the-art hadronic transport simulations. This white paper highlights the essential role that heavy-ion collision experiments and hadronic transport simulations play in understanding strong interactions in dense nuclear matter, with an emphasis on how these efforts can be used together with microscopic approaches and neutron star studies to uncover the nuclear EOS