Review on Quasi One-Dimensional CdSe Nanomaterials: Synthesis and Application in Photodetectors

Exploring temperature-dependent photoluminescence dynamics of colloidal CdSe nanoplatelets using machine learning approach

The study explore machine learning (ML) techniques to predict temperature-dependent photoluminescence (PL) spectra in colloidal CdSe nanoplatelets (NPLs), leveraging polynomial regression models trained on experimental data from 85 to 270 K spanning temperatures to forecast PL spectra backward to 0 K and forward to 300 K. 6th-degree polynomial models with Tweedie regression were optimal for band energy ([Formula: see text]) predictions up to 300 K, while 9th-degree models with LassoLars and Linear Regression regressors were suitable for backward predictions to 0 K. For exciton energy ([Formula: see text]), the Lasso model of degree 5 and the Ridge model of degree 4 performed well up to 300 K, while the Tweedie model of degree 2 and Theil-Sen model of degree 2 showed promise for predictions to 0 K. Furthermore, a GA-based approach was utilized to fit experimental data to theoretical model of Fan and Varshni equations, facilitating a comparative analysis with the ML-predicted curves.

Drift velocity saturation in field-effect transistors based on single CdSe nanowires

Field-effect transistors (FETs) based on semiconductor nanowires (NWs) have been extensively investigated and used for constructing novel nanoelectronic and optoelectronic devices in the past two decades. High electric field transport characteristics in FETs are of significance in both physics and applications. However, some specific physics phenomena at high electric field, such as drift velocity saturation, have rarely been reported in semiconductor NW FETs. In this work, the high electric field transport characteristics in FETs based on CdSe NWs were investigated. In the output characteristic curves, the current saturation phenomenon at high electric field caused by drift velocity saturation was observed. Typical values of saturation drift velocity and low electric field mobility in CdSe NW FETs were obtained. The low electric field mobility is in the range of 265.2 to 388.0 cm2 V-1 s-1. The saturation drift velocity is in the range of 5.1 × 105 to 7.0 × 105 cm s-1 and decreases monotonically with the increase of charge density, indicating that the electron-phonon scattering mechanism dominates at high electric field. Saturation drift velocity is an important figure-of-merit which characterizes the high electric field transport performance in FETs. As far as we know, this is the first experimental report on saturation drift velocity in CdSe NW FETs, which may provide valuable guidance for the design of nanoelectronic and optoelectronic devices based on CdSe NWs in the future.

Sonochemical Synthesis, Characterization and Optical Properties of Tb-Doped CdSe Nanoparticles: Synergistic Effect between Photocatalysis and Sonocatalysis

In this study, Tb-doped CdSe nanoparticles with variable Tb³⁺ content were synthesized by a simple sonochemical technique. The synthesized nanoparticles were characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and powder X-ray diffraction (XRD). The sono-photocatalytic activities of the as-prepared specimens were assessed for the degradation of Reactive Black 5. The experimental results show that the sono-photocatalytic process (85.25%) produced a higher degradation percentage than the individual sono- (22%) and photocatalytic degradation (8%) processes for an initial dye concentration and Tb-doped CdSe dosage of 20 mg/L and 1 g/L, respectively. Response surface methodology (RSM) was utilized to assess model and optimize the impacts of the operational parameters, namely, the Tb³⁺ content, initial dye concentration, catalyst dosage, and time. The addition of benzoquinone results in remarkably inhibited degradation and the addition of ammonium oxalate reduced the removal percentage to 24%. Superoxide radicals and photogenerated holes were detected as the main oxidative species.

Photoresponse of CdSe-PVA nanocomposite films at low magnetic fields

A set of nanocomposite films of poly-vinyl alcohol (PVA) and 0.1-0.4 wt% CdSe nanoparticles (NPs) were developed by spin coating and their surface resistance (R) was measured as a function of light illumination intensity (I_L ) and applied magnetic field (H). The ferromagnetic CdSe NPs were synthesized by a facile chemical method which ensured in situ surface stabilization with a skinny layer of graphitic carbon. The CdSe NPs were uniformly dispersed in an aqueous solution of 2.0 wt% PVA and spin-coated on fluorine-doped tin oxide coated glass substrates. The photoresponse of the nanocomposite films at low H exhibits their efficacy for pertinent applications in optoelectronics.

Electrospun Cadmium Selenide Nanoparticles-Loaded Cellulose Acetate Fibers for Solar Thermal Application

Solar thermal techniques provide a promising method for the direct conversion of solar energy to thermal energy for applications, such as water desalination. To effectively realize the optimal potential of solar thermal conversion, it is desirable to construct an assembly with localized heating. Specifically, photoactive semiconducting nanoparticles, when utilized as independent light absorbers, have successfully demonstrated the ability to increase solar vapor efficiency. Additionally, bio-based fibers have shown low thermal conductive photocorrosion. In this work, cellulose acetate (CA) fibers were loaded with cadmium selenide (CdSe) nanoparticles to be employed for solar thermal conversion and then subsequently evaluated for both their resulting morphology and conversion potential and efficiency. Electrospinning was employed to fabricate the CdSe-loaded CA fibers by adjusting the CA/CdSe ratio for increased solar conversion efficiency. The microstructural and chemical composition of the CdSe-loaded CA fibers were characterized. Additionally, the optical sunlight absorption performance was evaluated, and it was demonstrated that the CdSe nanoparticles-loaded CA fibers have the potential to significantly improve solar energy absorption. The photothermal conversion under 1 sun (100 mW/cm²) demonstrated that the CdSe nanoparticles could increase the temperature up to 43 °C. The CdSe-loaded CA fibers were shown as a feasible and promising hybrid material for achieving efficient solar thermal conversion.