A Comparative Study of Employees’ Perception Relating to Performance Appraisal Practices in the Public and Private Banking Sector of Sindh

Performance appraisal is a key human resource practice and source of a motivation for an employee and its success depends on justice perception of an employee towards performance appraisal system. Pakistani banking sector is playing a vital role in the economic growth of the country. Private Banks are innovative and effective in their approach as compared to the public banks. Past studies have compared the public and private banks and found that new private banks are more effective than public banks in terms of technical and economic efficiency. However, there are meager studies available in the context of justice perception of performance appraisal practices in the public and private banks. Data were collected through five-point Likert scale and analyzed with SPSS 24.0 versions. In the result difference of justice is measured by mean differences and independent sample t-test. However, it is found that employees of private banks perceive greater justice as compared to public banks. This study emphasizes the importance of fairness perception of employees in the context of performance appraisal practices and could be used to better understand the problems associated with appraisal practices in public and private banks.

Modified Optical Properties of Au Embedded Wide Band Gap Semiconductor Thin Films and Nanostructures

Wide bandgap semiconductors provide efficient absorption in UV and very low absorptions in the visible range of the electromagnetic spectrum. This limits their effectiveness in photocatalytic, photoactive and photosensitive devices. However, the optical properties of these semiconductors can be enhanced to provide increased absorptions in the visible range. The bandgap of the semiconductor can be modulated in several ways that include: doping, formation of heterostructures, quantum dots coupling, addition of metallic nanoparticles etc. In the present work, the surface plasmon resonance (SPR) energy of Au is utilized in three different semiconductor morphologies to tune the optical characteristics. Studies with three different dielectric environments such as: Au embedded planar, non-planar and Au coated wide bandgap semiconductors were performed. Specific studies of metal sandwiched planar (TiO2/Au/TiO2), heterostructure (ZnO/Au/TiO2) and Au coated ZnS nanostructures using various optical techniques that included spectroscopic ellipsometry, UV/Vis absorption and photoluminescence spectroscopy (PL) were performed in this work. The UV/Vis absorptions of TiO2/Au/TiO2 revealed the presence of two broad bands in the visible range, that were absent in TiO2 thin film, for both as-grown and annealed samples. This was attributed due to improved interband and plasmon resonance oscillations of Au in a dielectric environment. Spectroscopic ellipsometry of the Au, TiO2 and composite TiO2/Au/TiO2 films indicated that they carried the cumulative effect of UV and visible absorptions due to SPR phenomenon. The presence of interband transition was confirmed by fitting the experiment with the theoretical models, Tauc Lorentz model and Drude Lorentz model for TiO2 and Au, respectively. Dielectric functions obtained from ellipsometry were combined for the sandwiched structure using effective medium approximation (EMA) methods. The modelling showed the presence of interband transitions which provide improved absorption at Au/TiO2 interface. The values of Urbach energy which corresponds to TiO2 band tails extended into the visible region was also estimated. The increase in Urbach energy was xi a direct consequence of coupling of plasmons with the defect induced TiO2 band tail widened into the visible range. The effect of metal nanoparticles was observed in ZnO/Au/TiO2 nanoheterostructures in UV/Vis absorption and PL spectroscopy. The Au content embedded in the ZnO/Au/TiO2 composite was varied from 2-10 nm. It was observed that maximum absorptions in the structure occurred when Au content was varied to 6 nm (corresponding to the diameter of 9.8 ± 3.5 nm and density 1.4 x 1011 cm-2).Photoluminescence spectroscopy also revealed the maximum pinning of the defect states in TiO2 interface at 6 nm due to maximum participation of hot electrons injected through the SPR phenomenon. This study also highlighted the importance of dielectric layer and thickness surrounding the NPs as it affected the spread of Au NPs SPs resonant field. The third study comprised of the temperature dependent photoluminescence of ZnS nanostructures doped with two different elements, Mn and Sn. The defect centres in ZnS nanostructures provide very high luminescence. The coupling of these luminescent centres with the Au NPs altered the luminescence dynamics by introducing new charge transfer paths. In the present study, the overlapping of the Mn-induced defects with the SPR peak of Au resulted in quenching of UV peak corresponding to donor-acceptor transitions. While the Mn-induced defect overlapping the Au plasmon field was still present. Likewise, the presence of Au not only affected the defect-based transitions due to different ionic species in Sn-doped ZnS nanostructures but also activated the resonant processes in Sn, which is a semi-metal itself.