Near-infrared Region Of Electromagnetic Spectrum Research Articles

Theoretical Study on Polycarbonate-Based One-Dimensional Ternary Photonic Structures from Far-Ultraviolet to Near-Infrared Regions of Electromagnetic Spectrum

In the present research work, we have theoretically analyzed the photonic band-gap properties of one-dimensional photonic structures composed of polycarbonate and non-glass materials. These photonic structures, PC1, PC2, PC3 and PC4, are composed of alternating layers of polycarbonate/Al2O3, polycarbonate/MgF2, polycarbonate/BaF2 and polycarbonate/TiO2 materials, respectively. The period of each photonic structure is made up of a thin non-glass material layer sandwiched between two identical polycarbonate layers. The transfer matrix method has been used to investigate the transmission properties of PC1 to PC4. The comparison between the transmission spectra of PC1 to PC4 shows that the polycarbonate and TiO2-based photonic structure (PC4) possess three PBGs of zero transmission located at far-ultraviolet, visible and near-infrared regions of the electromagnetic spectrum at normal and oblique incidence (θ0 = 55°), both corresponding to TE wave only. The index of refraction of all five materials used in this study was obtained by applying the Sellmeier-type dispersion relationship to ensure accuracy in the results. The purpose of selecting polycarbonate along with Al2O3, TiO2, MgF2 or BaF2 as constituent materials of these photonic structures is due to the heat resistance properties of polycarbonate and the unique optical properties of oxide and fluoride materials with wide transparency from the ultraviolet to the near-infrared regions of the electromagnetic spectrum. The proposed work can be used to design some influential wavelength-selective reflectors composed of 1D PCs behind the active region of the solar cells for improving the photovoltaic performance of solar panels. This study can further be utilized for the fabrication of advanced solar cell designs consisting of 1D photonic mirror-based luminescence and reflection concentrators. The low temperature problem which arises in satellites may also be overcome with the help of smart windows based on the proposed multilayer structures.

APPLICATIONS OF CHEMICALLY SYNTHESIZED CUS: PBO ALLOYED THIN FILMS IN MULTILAYER SOLAR CELLS AND OPTOELECTRONICS

CuS: PbO, alloyed thin films were successfully deposited on glass substrates under the deposition condition of 40oC of NaOH solution, using two solution based methods: successive ionic layer adsorption and reaction (SILAR) and solution growth technique. The crystallographic studies were done using X-ray diffractometer (XRD) and scanning electron microscope (SEM). The deposited alloyed samples were annealed at 250oC and 1500C. using Master Chef Annealing Machine. Rutherford backscattering Spectroscopy (RBS) analysis confirmed the percentage of the elements of copper, lead, sulphur and oxygen in the alloyed thin films. The optical characterization was carried out using UV-1800 double beam spectrophotometer. Sample cp1 annealed at 250 oC has an optical transmittance of 27% -71% in the ultraviolet region, 71%-83% in the visible and 83%-88% in the near infrared regions of electromagnetic spectrum. The alloyed thin films of samples cp2 of CuS:PbO annealed at 150oC, show optical transmittance of 15%-61% in the ultraviolet region, 61%-59% in the visible, and becomes linear through the near-infrared regions of electromagnetic spectrum. The two samples, have equal direct wide band gap of 3.65±0.05eV. From the spectral qualities, these compounds alloyed thin films may found useful in passive layer in heat and cold mirror application, vulcanization in tyre production due its thermal stability, active multilayer in various types of solar cells, liquid crystal displays, flat panel displays for optoelectronic applications and gas censor applications.

Synthesis of CdO:SnO2 alloyed thin films for solar energy conversion and optoelectronic applications

CdO:SnO2, alloyed thin films were successfully deposited on glass substrates under the deposition condition of 60 °C of NaOH solution, using two solution based methods: successive ionic layer adsorption and reaction and solution growth technique. The crystallographic studies were done using X-ray diffractometer and scanning electron microscope. The deposited alloyed samples were annealed between 100 and 250 °C using Master Chef Annealing Machine. Rutherford backscattering Spectroscopy analysis confirmed the percentage of the elements of cadmium, tin, and oxygen in the alloyed thin films. The optical characterization was carried out using UV-1800 double beam spectrophotometer. The alloyed thin films of samples A14 and A16 of CdO:SnO2 show optical transmittance of 16–60% in the ultraviolet region, 61–59% in the visible, and 59–58% in the near-infrared regions of electromagnetic spectrum for sample A14 annealed at 100 °C. Sample A16 annealed at 150 °C has an optical transmittance of 27–70% in the ultraviolet region, 70–84% in the visible and 85–87% in the near infrared regions of electromagnetic spectrum. The two samples, have equal direct wide band gap of 3.70 ± 0.05 eV. From the spectral qualities, these compound alloyed thin films may be found useful in heat mirror applications, active layer in various types of solar cells and passive layer in heat and cold mirror application, galvanizing materials. It can also found interesting as semiconductor materials for electronic applications.

Composition dependent optical, structural and photoluminescence characteristics of cesium tin halide perovskites

Compositionally tunable photoluminescence from environment friendly tin based inorganic perovskites covering the visible to near-infrared regions of electromagnetic spectrum.