The current status of the use of nanoparticles for photothermal treatments is reviewed in detail. The different families of heating nanoparticles are described paying special attention to the physical mechanisms at the root of the light-to-heat conversion processes. The heating efficiencies and spectral working ranges are listed and compared. The most important results obtained in both in vivo and in vitro nanoparticle assisted photothermal treatments are summarized. The advantages and disadvantages of the different heating nanoparticles are discussed.

Nanoparticles for photothermal therapies.

CuO nanostructures: Synthesis, characterization, growth mechanisms, fundamental properties, and applications

The quantum-confined Stark effect in single cadmium selenide (CdSe) nanocrystallite quantum dots was studied. The electric field dependence of the single-dot spectrum is characterized by a highly polarizable excited state (∼10 5 cubic angstroms, compared to typical molecular values of order 10 to 100 cubic angstroms), in the presence of randomly oriented local electric fields that change over time. These local fields result in spontaneous spectral diffusion and contribute to ensemble inhomogeneous broadening. Stark shifts of the lowest excited state more than two orders of magnitude larger than the linewidth were observed, suggesting the potential use of these dots in electro-optic modulation devices.

Quantum Confined Stark Effect in Single CdSe Nanocrystallite Quantum Dots

This review introduces quantum dots (QDs) and explores their properties, synthesis, applications, delivery systems in biology, and their toxicity. QDs are one of the first nanotechnologies to be integrated with the biological sciences and are widely anticipated to eventually find application in a number of commercial consumer and clinical products. They exhibit unique luminescence characteristics and electronic properties such as wide and continuous absorption spectra, narrow emission spectra, and high light stability. The application of QDs, as a new technology for biosystems, has been typically studied on mammalian cells. Due to the small structures of QDs, some physical properties such as optical and electron transport characteristics are quite different from those of the bulk materials.

/pdf/quantum-dots-synthesis-bioapplications-and-toxicity-3ndmrsbe73.pdf

Quantum dots: synthesis, bioapplications, and toxicity.

Core/shell nanoparticles in biomedical applications.

Semiconducting quantum dots, whose particle sizes are in the nanometer range, have very unusual properties. The quantum dots have band gaps that depend in a complicated fashion upon a number of factors, described in the article. Processing-structure-properties-performance relationships are reviewed for compound semiconducting quantum dots. Various methods for synthesizing these quantum dots are discussed, as well as their resulting properties. Quantum states and confinement of their excitons may shift their optical absorption and emission energies. Such effects are important for tuning their luminescence stimulated by photons (photoluminescence) or electric field (electroluminescence). In this article, decoupling of quantum effects on excitation and emission are described, along with the use of quantum dots as sensitizers in phosphors. In addition, we reviewed the multimodal applications of quantum dots, including in electroluminescence device, solar cell and biological imaging.

https://www.mdpi.com/1996-1944/3/4/2260/pdf

Quantum Dots and Their Multimodal Applications: A Review

We report the use of a solution-processed ZnO nanoparticle buffer layer in hybrid solar cells based on blends of poly(3-hexylthiophene) (P3HT) and CdSe quantum dots. Depending on the size of the CdSe nanocrystal, these devices exhibit 20–70% higher photocurrent output than similar devices without the ZnO nanoparticle layer, which is attributed to a combination of electronic and optical effects. With negligible change in open-circuit voltage and a small increase in the fill factor, the power conversion efficiency of these P3HT:CdSe hybrid solar cells was increased by 30–80% with incorporation of the ZnO nanoparticle layer. The presence of the ZnO nanoparticle layer also drastically improves the stability of these hybrid solar cells. Less than 40% loss in efficiency was observed for such devices after 70 days of exposure to the laboratory ambient without any type of encapsulation.

Teng Kuan Tseng

Papers

Quantum Dots and Their Multimodal Applications: A Review

Hybrid polymer-CdSe solar cells with a ZnO nanoparticle buffer layer for improved efficiency and lifetime