Abstract It is particularly appealing for efficient active terahertz (THz) modulators using photonic structures to enhance light–matter interaction. Here, an optical controlled THz modulator proposed that combines lead sulfide (PbS) quantum dots with subwavelength metallic split-ring resonators (SRRs) providing field enhancement. The modulation depth reaches 60.3%, which approximately 3 times l...

The effect of lead sulfide (PbS) quantum dots (QDs) on the photoelectrochemical properties of TiO2 with a varied number of SILAR cycles has been investigated. The study has also highlighted physical processes including band alignment, charge recombination and transportation for a PbS QDs/TiO2 interface. The inclusion of PbS QDs underneath TiO2 thin film has significantly enhanced the PEC respon...

In this paper, we report the use of lead sulfide quantum dot (PbS QD) bioconjugates as near infrared (NIR) contrast agents for targeted molecular imaging with expanded emission wavelengths beyond 1000 nm. The red-shifted emission band, coupled with the small particle size, which will facilitate clearance, both afford PbS QDs unique properties for noninvasive, high resolution in vivo NIR imaging...

Heterostructures, combining perovskite nanocrystals (PNC) and chalcogenide quantum dots, could pave a path to optoelectronic device applications by enabling absorption in the near-infrared region, tailorable electronic properties, stable crystal structures. Ideally, heterostructure host material requires similar lattice constant as guest which is also constrained synthesis protocol materials se...

The optical and structural properties of cadmium and lead sulfide nanocrystals deposited on mesoporous TiO2 substrates via the successive ionic layer adsorption and reaction method were comparatively investigated by reflectance, transmittance, micro-Raman and photoluminescence measurements. Enhanced interfacial electron transfer is evidenced upon direct growth of both CdS and PbS on TiO2 throug...

Lead sulfide ~PbS! thin films were deposited from a chemical bath onto SiO2 /Si ~n-type! substrates. Pseudo-metal–oxide–semiconductor devices were obtained by evaporating source and drain gold electrodes on a PbS surface and aluminum gate electrode on a Si substrate. Field-effect-assisted photoconductivity in the PbS layer was investigated at room temperature, in the 800– 2700-nm-wavelength dom...

Although the stoichiometry of bulk lead sulfide (PbS) is exactly 1:1, that of quantum dots (QDs) can be considerably different from this crystalline limit. Employing first-principles calculations, we show that the impact of PbS QD stoichiometry on the electronic structure can be enormous, suggesting that control over the overall stoichiometry in the QD will play a critical role for improving th...

In this work; Lead sulfide (PbS) plasma plume was prepared by laser induced (LIP). With Nd: YAG irradiation of the target worked at a wavelength (1064) nm. have been studied using spectrometer that collect spectrum Laser produce PbS different values energy (200,300,400,500,600)mJ. The electron temperature (Te), density ne, Debye length (λD) and frequency (fp) were determined optical emission sp...

In a recent paper (Lewis et al 2010 Nanotechnology 21 45502) proposed a previously unidentified gap state within lead sulfide nanocrystals (PbS-NCs) based on analysis of their temperature dependent optical properties. In the following we argue that due to oversights in the analysis of the data presented, inconsistencies arise which question their exclusion of 'dark' excitonic states as the orig...