Phosphorus Oxidation Controls Epitaxial Shell Growth in InP/ZnSe Quantum Dots.

InP/ZnSe/ZnS core/shell/shell quantum dots are the most investigated quantum dot material for commercial applications involving visible light emission. The inner InP/ZnSe interface is complex since it is not charge balanced, and the InP surface is prone to oxidation. The role of oxidative defects at this interface has remained a topic of debate, with conflicting reports of both detrimental and beneficial effects on the quantum dot properties.

Near-Unity Photoluminescence Quantum Yield of Core-Only InP Quantum Dots a Simple Postsynthetic InF Treatment.

Indium phosphide (InP) quantum dots (QDs) are considered the most promising alternative for Cd and Pb-based QDs for lighting and display applications. However, while core-only QDs of CdSe and CdTe have been prepared with near-unity photoluminescence quantum yield (PLQY), this is not yet achieved for InP QDs. Treatments with HF have been used to boost the PLQY of InP core-only QDs up to 85%.

Solvation Shifts the Band-Edge Position of Colloidal Quantum Dots by Nearly 1 eV.

The optoelectronic properties of colloidal quantum dots (cQDs) depend critically on the absolute energy of the conduction and valence band edges. It is well known these band-edge energies are sensitive to the ligands on the cQD surface, but it is much less clear how they depend on other experimental conditions, like solvation. Here, we experimentally determine the band-edge positions of thin films of PbS and ZnO cQDs via spectroelectrochemical measurements.

Measuring Mitochondrial Oxygen Tension during Red Blood Cell Transfusion in Chronic Anemia Patients: A Pilot Study.

In light of the associated risks, the question has been raised whether the decision to give a blood transfusion should solely be based on the hemoglobin level. As mitochondria are the final destination of oxygen transport, mitochondrial parameters are suggested to be of added value. The aims of this pilot study were to investigate the effect of a red blood cell transfusion on mitochondrial oxygenation as measured by the COMET device in chronic anemia patients and to explore the clinical usability of the COMET monitor in blood transfusion treatments, especially the feasibility of performing measurements in an outpatient setting.

Numerical Model to Simulate Electrochemical Charging of Nanocrystal Films.

Electrochemical charging of nanocrystal films opens up new possibilities for designing quantum dot-based device structures, but a solid theoretical framework of this process and its limitations is lacking. In this work, drift-diffusion simulations are employed to model the charging of nanocrystal films and gain insight into the electrochemical doping process. Through steady state simulations it is shown that the Fermi level and doping density in the nanocrystal film depend on the concentration of the electrolyte in addition to the value of the applied potential.