2 research outputs found
Superatom Molecular Orbital as an Interfacial Charge Separation State
Hot
electron cooling by energy loss to heat through electron–phonon
(e–ph) interaction is an important mechanism that can limit
the efficiency of solar energy conversion. To avoid such energy loss,
sufficient charge separation needs to be realized by extracting hot
carriers from the photoconverter before they cool, which requires
fast interfacial charge transfer and slow internal hot carrier relaxation.
Using ab initio time-dependent nonadiabatic molecular dynamics and
taking C<sub>60</sub>/MoS<sub>2</sub> as a prototype system, we show
that the superatom molecular orbitals (SAMOs) of fullerenes, which
are bound by the central potential of the whole molecule induced by
the charge screening, are ideal media for charge separation. The diffuse
character of SAMOs results in extremely weak e–ph interaction
and therefore acts as a “phonon bottleneck” for hot
electron cooling. Furthermore, it also leads to significant hybridization
with other atoms at the interface that induces fast charge transfer.
The interfacial charge-transfer rate at the C<sub>60</sub>/MoS<sub>2</sub> interface is found to be 2 orders of magnitude faster than
the hot electron cooling from <i>s</i>-SAMO in C<sub>60</sub>. This conclusion is generally applicable for different carbon nanostructures
that have SAMOs. The proposed SAMO-induced charge separation provides
unique and essential insights into the material design and function
for solar energy conversion
Additional file 1 of Evaluating the progression to abnormal thyrotropin in euthyroid preconception women: a population-based study
Additional file 1: Supplemental Figure 1. Flowchart of the study cohort selection criteria with excluding individuals who were not suitable for pregnancy at baseline