Mittal, Vinita Mid-infrared Integrated photonic devices for biosensing. University of Southampton, Doctoral Thesis, pp. Thesis Doctoral Abstract This thesis describes the realisation of devices and techniques based on evanescent field sensing using planar optical waveguides for mid-infrared MIR absorption spectroscopy, to provide bio-chemical sensing capabilities for medical diagnostics. The fundamental vibrations of bio-chemical molecules occur in the MIR region, where their absorption is orders of magnitude stronger than their overtone bands in the near-infrared making it suitable for highly sensitive and specific absorption spectroscopy.
Vijay Fulari Sambhaji Shinde Vol. ZnSe thin films are successfully deposited by spray pyrolysis deposition technique. Deposited thin films are characterized by X-ray diffraction study, and it reveals that spray-deposited ZnSe thin films are polycrystalline with hexagonal crystal structure.
Surface morphology is carried out by scanning electron microscopy. It shows cotton-like morphology, and optical properties, such as absorbance, transmittance, reflectance, band gap, refrac- tive index, extinction coefficient are studied.
Photoluminescence shows strong emission at nm. Also, spray- deposited ZnSe thin films are hydrophilic in nature, which is shown by contact angle meter.
In particular, ZnSe-based materials have ZnSe thin films were deposited on ultrasonically cleaned been widely investigated in recent years for their potential glass substrate by spray pyrolysis technique using aqueous so- optoelectronic applications.
The ZnSe thin films were n-type semiconducting material with direct band gap 2. Hence ZnSe is mostly used in pho- cleaned glass substrate kept at K. In total, 50 mL of the 0. So many reports are available on the spray- SeO2 solution was used and sprayed for 15 min.
In the spray- deposited ZnO thin film by Shinde et al.
The distance between the nozzle and the substrate was main- Also, other deposition methods show the different nano- tained at 35 cm and the substrate temperature of K was structures for ZnSe thin film. Recently, Hu et al. The annealing ported cotton-candy-like morphology for SiO.
To the best of process was carried out by heating at K for 60 min. If more our knowledge we are reporting for first time cotton-like mor- than 50 mL solution was used, then powder was formed on the phology for spray-deposited ZnSe thin film. When less than 50 mL was used, then film thickness re- In the present investigation, we have successfully syn- duced.
The optimized film thickness is used for further structural, morphological, optical, and photoluminescence study. So, in the present investigation, we have success- D2 phaser table-top model.
Experiment optical reflectance was recorded using a Steller Net. All the reagents used in this experiment were of analytical The photoluminescence study was made using Bruker spec- reagent grade and used without further purification.
The cotton-like mor- phology is observed of ZnSe film. Figure 2 b shows the zoomed cotton image and inset of Fig. When ZnSe solution is sprayed on the glass plate, the maintained temperature is high K due to the high temper- ature water content being evaporated.
This evaporation process is responsible for cotton-like morphology; also these films are annealed at K. Hence SEM morphology looks like spread cotton.
Optical properties When a ray of light passes through the material or a thin film so many phenomena are observed such as absorbance, Fig. XRD pattern of spray-deposited ZnSe thin film. When we discuss the relationship between the absorbance, 3.
Results and discussion transmittance and reflectance for bulk material we always refer to Eq. It is observed that all films deposited by spray pyrolysis ZnSe are where A is the absorbance, T is transmittance, and R is re- polycrystalline in nature having hexagonal crystal structure, flectance, but when we discuss the optical properties for thin The XRD patterns show diffraction peaks at If the frequency of the travelling light is resonant planes.
The width of peak is found to be 0. The with the transition frequencies of the ZnSe atoms then absorp- small peaks at The strain, tion technique. It is observed that there are absorbance peaks dislocation density and number of crystals per unit area were at nm and nm, which may be due to SeO2 because se- calculated using Eqs.
Usually in the ZnSe 4 more transmittance has been observed but here we observed 15" the decrease in transmittance.Advances in Composites: Research on Sodium Citrate for Pulse Electrodeposition ZnSe Thin Films.
Nanostructures of diverse chemical nature are used as biomarkers, therapeutics, catalysts, and structural reinforcements.
The decoration with surfactants has a long history and . Read "Optical characterization of ZnSe thin films, Proceedings of SPIE" on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
PhD thesis of Sumbit Chaliha of Gauhati University () on the topic STUDIES OF ZnSe AND INDIUM TIN OXIDE BASED THIN FILM SCHOTTKY BARRIERS AND HETEROJUNCTIONS FOR THEIR ELECTRICAL AND OPTICAL. This thesis mainly aims at understanding the mechanisms of metal alloying and selenization occurring during step (ii), and their effects on the microstructure of the final film, the presence of secondary phases and their distribution in the thin films synthesized.
We demonstrate a solution-processed large-area method to fabricate intrinsic and silver (Ag)-doped ZnSe thin films with tunable electrical and optical properties. The resulting films were extensively characterized and incorporated as the active layer for TFTs (thin film transistors) and as the buffer layer i.