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According to the infrared attenuation spectrum, we can know the conduction type and major point defect of CdZnTe crystals. Based on point defect modelling, an appropriate modus of atmosphere annealing was described in this paper. In this paper, annealing with Cd pressure control technology was used to upgrade p-CdZnTe and n-CdZnTe, respectively. Characterizations reveal that the optical and electrical performance of the CZT crystals is patently improved after annealing. Employment of the infrared attenuation spectrum as the annealing guideline has been verified to be feasible and effectual in this paper. [ABSTRACT FROM AUTHOR]

In this paper, Ag nanoparticles were successfully prepared by chemical reduction, and then Ag/ZnO composite particles were successfully prepared and deposited onto glass substrates to form Ag/ZnO thin films. Hereafter, the structure, the morphology and the metal enhanced fluorescence (MEF) property of Ag nanoparticles and ZnO/Ag composite particles were studied by XRD, SEM, EDS, TEM, UV-vis absorption and fluorescence (FL) spectrometer. The results showed that the average size of Ag nanoparticles increased with the increase of prepared time. Moreover, ZnO layer consisted of polycrystalline structure and amorphous interface layer, but nano-Ag particle was polycrystalline structure. Annealing process was carried out to investigate the influence of annealing process parameters on MEF property of Ag/ZnO composite structure. Due to annealing treatment, the amorphous component of Ag/ZnO thin films was reduced, which might improve the density of Ag/ZnO thin films and the diameter of composite particles. Furthermore, FL enhancement phenomenon of fluorescein isothiocyanate (FITC) molecules might be attributed to the joint influence of the roughness and the density of these films and the average diameter of composite particles. [ABSTRACT FROM AUTHOR]

We report on a first-principle theoretical investigation of the optical absorption and emission spectra of poly(3-hexylthiophene) (P3HT) aggregates by means of a multiscale all-atom hybrid approach, which combines: (i) molecular dynamics simulations of (intrachain) conformational and (interchain) positional disorder, (ii) quantum-chemical calculations of intrachain excited states and excitonic interactions, and (iii) solving of a Frenkel–Holstein model that includes coupling of the electronic excitations to a dominant high-frequency molecular vibration. The modeling work points to the co-existence of ordered nano-aggregates into disordered domains, with the former dominating the emission spectrum while both regions contribute to the absorption spectrum. The measured photoluminescence line shape and the Stokes shift are both reproduced by the theory for aggregates comprising polymer chain with lengths ∼35–40 repeating units. [ABSTRACT FROM AUTHOR]

CdTe thin films have been prepared by electrochemical deposition. The morphological, structural, and optical properties of CdTe thin films deposited with different deposition time were investigated, and the influence of film thickness on the photoelectric characteristics of CdTe thin films was studied. At the deposition time of 1.5 h, CdTe thin films had good optical properties and the photocurrent reached 20 μAcm−2. Furthermore, the Pt/CdS/CdTe/FTO structure was prepared to improve its PEC stability and the photocurrent of 240 μAcm−2 had been achieved. [ABSTRACT FROM AUTHOR]

The electrical performances and optical properties of p-type amorphous silicon oxide (p-SiO x ) thin films with gradient refractive index are studied. The composite thin films as antireflective coatings (ARCs) are widely used in solar cells and microelectronic devices. The double-layer p-SiO x thin films are deposited by plasma-enhanced chemical vapor deposition (PECVD) system. To obtain better optical properties, the refractive index of ARCs can be adjusted by SiH 4 to N 2 O ratio. And the electrical performances of composite thin films can be improved by adjustment of B 2 H 6 to SiH 4 ratio. The computational model is built to predict the optimized range of reflection spectra corresponding to structure of p-SiO x ARCs with gradient refractive index by finite difference time domain (FDTD) method. It shows the difference of reflection spectra with gradient refractive index distribution. The optimized reflection spectra simulated by FDTD method confirms to agree well with that measured by UV–visible spectroscopy. [ABSTRACT FROM AUTHOR]

In this work, B and Ga co-doped ZnO (BGZO) films were fabricated by RF magnetron sputtering method. The effects of substrate temperature on the electrical, optical, structural and morphological properties of B and Ga co-doped ZnO films were investigated. XRD results revealed that deposited films were textured along c-axis and maintain wurtzite crystalline symmetry. As substrate temperature increased up to 200 °C, the film crystallinity was improved and the crystallite sizes became larger. At the substrate temperature of 200 °C, the films showed lower resistivity, higher Hall mobility and higher optical band gap. It was also observed that all films showed high transparency in the visible range (400–800 nm), which did not change obviously with the substrate temperature. [ABSTRACT FROM AUTHOR]

In this paper, Cu doped CdS thin films were prepared on FTO substrates by RF magnetron sputtering and then were annealed at 350 °C–425 °C in vacuum for 20 min. The influences of different Cu-doped concentrations (Cu 4.1, 5.4, 7.3, 9.1 at%) on morphological, structural, optical properties and photo-electrochemical (PEC) properties of CdS thin films were investigated. The PEC characterizations indicated that the photocurrent densities of CdS:Cu (Cu 4.1, 5.4, 7.3, 9.1 at%) thin films increased from 0.94, 1.28,1.86,1.91 mA cm−2 to 1.33, 1.89, 2.40, 3.16 mA cm−2 after annealing. And the PEC properties of CdS:Cu thin films annealed at different temperatures were also studied. FTO/annealed CdS:Cu/Pt photoanode were fabricated to enhance the photocurrent activity and the photocurrent density of FTO/annealed CdS:Cu/5 nm Pt is 1.5 times larger than that of the CdS:Cu electrode without Pt cocatalyst. • CdS:Cu thin films were firstly prepared by magnetron sputtering method. • PEC properties of n type CdS:Cu thin films were firstly studied. • FTO/CdS:Cu/Pt improved PEC performances of CdS:Cu thin films. [ABSTRACT FROM AUTHOR]

• Magnesium-doped zinc oxide (MGZO) films are successfully deposited on glass substrates by magnetron sputtering system. • Surface roughness of MGZO film enlarges with substrate temperature increasing. • The band-gap of MGZO film is enhanced by substrate temperature increasing. • The luminescence performance of MGZO film is improved with larger substrate temperature. Magnesium-doped zinc oxide (MGZO) films were deposited on glass substrates by magnetron sputtering system. The effects of substrate temperature on microstructure and optical properties of MGZO films were firstly investigated. Based on XRD results, the full width at half maximum (FWHM) of MGZO film reaches the value of 0.27° at 300 ℃, illustrating the film quality is enhanced via substrate temperature increasing. The band-gap of MGZO film increases with substrate temperature increasing. Alternatively, the photoluminescence quality of MGZO film can be enhanced by the substrate temperature, resulting from the increasing ratio of I 380nm to I 540nm. The ratio achieves the value of 3.2 at 500 ℃. This work can offer a feasible approach to tailor the microstructure and optical properties of MGZO film. [ABSTRACT FROM AUTHOR]