7 research outputs found
Global Control of CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> Formation with Multifunctional Ionic Liquid for Perovskite Hybrid Photovoltaics
Here,
a simple strategy using 1-butyl-3-methylimidazolium iodide
(BMII) as a multifunctional additive was employed to globally modify
the two-step deposition process of the perovskite film. Morphological,
structural, and spectral analyses showed that the BMII additive could
coordinate with PbI<sub>2</sub> and thereby retarded the reaction
of PbI<sub>2</sub> and CH<sub>3</sub>NH<sub>3</sub>I through the ionic
exchange process. Moreover, the residual BMII provided a liquid domain
to promote the coarsening of the perovskite crystal during the thermal
annealing process. Thus, the obtained MAPbI<sub>3</sub> film preferred
low PbI<sub>2</sub> residue, high-quality crystallization, and large-grained
microstructure. Using films prepared with BMII additives, the maximum
power conversion efficiency of the solar cells was improved from 12.6%
of the reference cell to 15.6%. The present study gives a reproductive
and facile strategy toward high quality of perovskite thin films and
efficient solar cells
Correlating Multichannel Charge Transfer Dynamics with Tilt Angles of Organic Donor–Acceptor Dyes Anchored on Titania
Attaching the side chains onto the
electronic backbone of photosensitizing
dye molecules has been a widely employed method to enhance the performance
of dye-sensitized solar cells (DSCs). However, at the present time
the interfacial microstructure as well as its influence on the charge
transfer dynamics have not been fully comprehended, both of which
underpin the phenomenological photovoltaic characteristics. In this
work, we derived the tilt angles of two organic donor–acceptor
dyes anchored on the surface of titania by X-ray reflectivity measurements
and probed the broad time scale dynamics of charge transfer reactions
in DSCs, unveiling the intrinsic roles of bulky or branched side chains
attached to the conjugated segment in modulating photovoltaic behaviors
Adsorption Energy Optimization of Co<sub>3</sub>O<sub>4</sub> through Rapid Surface Sulfurization for Efficient Counter Electrode in Dye-Sensitized Solar Cells
High-efficiency
electrocatalysts have been widely applied in various
fields, especially in the counter electrode (CE) of dye-sensitized
solar cells (DSSCs). Different from the usual methods for developing
high-performance CE materials through searching new materials and designing new nanostructure, we
utilized a rapid surface sulfurization treatment to activate the well-known
Co<sub>3</sub>O<sub>4</sub> material by increasing the adsorption
energy of iodine (I) atom in the electrolyte of DSSCs. The density
functional theory (DFT) calculation indicated the adsorption energy
of Co<sub>3</sub>O<sub>4</sub> (<i>E</i><sub>ad</sub><sup>I</sup> 0.347 eV) toward I atom was
dramatically increased to 0.835 eV through just transforming Co<sub>3</sub>O<sub>4</sub> at surface into Co<sub>3</sub>S<sub>4</sub>.
After a short activation time of 30 s, Co<sub>3</sub>O<sub>4</sub> CEs showed a superior catalytic performance toward iodide electrolyte
comparable with traditional Pt CE, generating a power conversion efficiency
of 8.6% in DSSCs. This method of adjusting adsorption energy via surface
sulfurization is applicable in the activation of other metal oxides,
and provides a convenient but efficient way to modify the simple abundant
materials for their different electrocatalytic applications
Change of intraoperative core temperature during operations.
<p>Patients’ core temperature was measured at the tympanic membrane beginning every 15 minutes after the induction of anesthesia until the end of the operation. A total of 3132 subjects were enrolled in the study; each curve represents a connection of 5 percentiles, 25 percentile, 50 percentile, 75 percentile and 95 percentile of core temperature at a specific time point. The time interval is 15 minutes.</p
Incidence of intraoperative hypothermia, patient warming and clinical outcome (N = 3132).
<p>Incidence of intraoperative hypothermia, patient warming and clinical outcome (N = 3132).</p
Risk factors associated with intraoperative hypothermia.
<p>Risk factors associated with intraoperative hypothermia.</p