Field emission from two-dimensional (2D) CdSSe flake flowers structure grown on gold coated silicon substrate: An efficient cold cathode

Field emission finds a vital space in numerous scientific and technological applications, including high-resolution imaging at micro- and nano-scales, conducting high-energy physics experiments, molecule ionization in spectroscopy, and electronic uses. A continuous effort exists to develop new materials for enhanced field emission applications. In the present work, two-dimensional (2D) well-aligned CdSSe flake flowers (CdSSe-FFs) were successfully grown on gold-coated silicon substrate utilizing a simple and affordable chemical bath deposition approach at ambient temperature. The time-dependent growth mechanism from nanoparticles to FFs was observed at optimized parameters such as concentration of precursors, pH (~11), deposition time, and solution temperature. The crystalline nature of CdSSe-FFs is confirmed by high-resolution transmission electron microscopy (HRTEM) results, and selected area electron diffraction (SAED) observations reveal a hexagonal crystal structure. Additionally, the CdSSe-FFs thickness was confirmed by TEM analysis and found to be ~20-30 nm. The optical, photoelectric, and field emission (FE) characteristics are thoroughly explored which shows significant enhancement due to the formation of heterojunction between the gold-coated silicon substrate and CdSSe-FFs. The UV-visible absorption spectra of CdSSe-FFs show enhanced absorption at 700 nm, corresponding to the energy band gap (Eg) of 1.77 eV. The CdSSe-FFs exhibited field emission and photosensitive field emission (PSFE) characteristics. In FE study CdSSe-FFs shows an increase in current density of 387.2 μ A cm-2 in an applied field of 4.1 V m-1 which is 4.08 fold as compared to without light illumination (95.1 μ A cm-2). Furthermore, it shows excellent emission current stability at the preset value of 1.5 μA over 3 h with a deviation of the current density of less than 5% respectively. RESEARCH HIGHLIGHTS: Novel CdSSe flake flowers were grown on Au-coated Si substrate by a cost-effective chemical bath deposition route. The growth mechanism of CdSSe flake flowers is studied in detail. Field emission and Photoluminescence study of CdSSe flake flowers is characterized. CdSSe flake flowers with nanoflakes sharp edges exhibited enhanced field emission properties.

Multi-elemental chalcogeniden-BiCdSe films grown under controlled depth voltammetry: improved photo-electrochemical behaviour toward energy conversion

In this study, a combinatorial approach was developed for fabricating nanostructured composite semiconductor matrices, which exhibited promising photo-response, appreciable photo-current potential and enhanced energy conversion efficiency.

Sunlight Promotes Fast Release of Hazardous Cadmium from Widely-Used Commercial Cadmium Pigment

Cadmium pigments are widely used in the polymer and ceramic industry. Their potential environmental risk is under debate, being the major barrier for appropriate regulation. We show that 83.0 ± 0.2% of hazardous cadmium ion (Cd²⁺) was released from the commercial cadmium sulfoselenide pigment (i.e., cadmium red) in aqueous suspension within 24 h under simulated sunlit conditions. This photodissolution process also generated sub-20 nm pigment nanoparticles. Cd²⁺ release is attributed to the reactions between photogenerated holes and the pigment lattices. The photodissolution process can be activated by both ultraviolet and visible light in the solar spectrum. Irradiation under alkaline conditions or in the presence of phosphate and carbonate species resulted in reduced charge carrier energy or the formation of insoluble and photostable cadmium precipitates on pigment surfaces, mitigating photodissolution. Tannic acid inhibited the photodissolution process by light screening and scavenging photogenerated holes. The fast release of Cd²⁺ from the pigment was further confirmed in river water under natural sunlight, with 38.6 ± 0.1% of the cadmium released within 4 h. Overall, this study underscores the importance to account for photochemical effects to inform risk assessments and regulations of cadmium pigments which are currently based on their low solubility.

Voltammetric deposition of BiCdTe composite films with improved functional properties for photo-electrochemical cells

n-Type BiCdTe nanostructured films produced by periodic voltammetry exhibit high photo-conversion efficiency and significantly promote charge transport across the electrode/electrolyte interface.

Photocurrent enhancement in a Cu2Cd(SSe)2 photoanode synthesized via an arrested precipitation route

Nanostructured combinatorial quaternary Cu₂Cd(SSe)₂ thin films synthesized via a self organized arrested precipitation technique for photoelectrochemical cell performance.