Global Control of CH₃NH₃PbI₃ 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 PbI₂ and thereby retarded the reaction of PbI₂ and CH₃NH₃I 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 MAPbI₃ film preferred low PbI₂ 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 Co₃O₄ 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 Co₃O₄ 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 Co₃O₄ (<i>E</i>_ad^I 0.347 eV) toward I atom was dramatically increased to 0.835 eV through just transforming Co₃O₄ at surface into Co₃S₄. After a short activation time of 30 s, Co₃O₄ 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

Outcome of hypothermia and normothermia.

<p>Outcome of hypothermia and normothermia.</p