Photoluminescence analysis is a useful method to study the optical properties of semiconductor nanostructures. Distinct processes take place to result in the light emission from the nanostructure. Various deposition methods and morphologies changed the emission band in semiconductor nanostructures. Three different morphology of Lead Sulfide structures such as nonospheres, star-shaped and dendrite nanostructures have been analyzed and the Photoluminescence results were compared. In three cases, band emissions are in visible region and it was observed that the incidence of quantum limits in resulting of increasing surface to volume ratio is impressive to optical properties. تفاصيل المقالة

Lead sulfide (PbS) nanostructures are one of the possible candidates to be used in modern optic devices. It can be deposited by various methods. Composition of the deposited layers and their optical properties can be determined by Raman spectroscopy. In this work, Raman features of PbS nanostructures are discussed in detail. Several different morphology of PbS nanostructures such as nonocubics, hexapod and octahedron was studied. Their size and morphologies are expressed and discussed about their Raman spectrum. In each case, represented the reason of the any Raman peaks and finally, it has been tried to be a comparison between them. تفاصيل المقالة

Nanoparticles (NPs) are causing threats to the environment. In this review, we examined how hematite (Fe2O3) and cobalt oxide (Co2O3) nanoparticles impact the species of freshwater green algae Chlorella vulgaris (C. vulgaris). We exposed laboratory cultures to five initial concentrations of nanoparticles and measured impacts on species in 24, 48, 72, 96, 120, and 144 hours in Karun River water at 20-25°C. Our results indicated that Fe2O3and Co2O3 NPs significantly (dependent on concentration) reduced the chlorophyll a, b, and carotenoid contents of algae C. vulgaris compared to the control group (P <0.05). Also, due to the combination of these two nanoparticles, Co2O3 (50 Fe2O3+100 Co2O3) has a more negative effect on algae chlorophyll change. According to the data, the exposure concentration was also found to be a more effective factor in the Chlorophyll content in algae species as compared to the exposure time. Our study suggests this nanoparticle has potential to affect aquatic life and ecosystem properties of freshwater habitats. تفاصيل المقالة