Sub-bandgap photoluminescence properties of multilayer h-BN-on-sapphire.

Two-dimensional hexagonal boron nitride (h-BN) materials have garnered increasing attention due to its ability of hosting intrinsic quantum point defects. This paper presents a photoluminescence (PL) mapping study related to sub-bandgap-level emission in bulk-like multilayer h-BN films. Spatial PL intensity distributions were carefully analyzed with 500 nm spatial resolution in terms of zero phonon line (ZPL) and phonon sideband (PSB) emission-peaks and their linewidths, thereby identifying the potential quantum point defects within the films. Two types of ZPL and PSB emissions were confirmed from the point defects located at the non-edge and edge of the films. Our statistical PL data from the non-edge- and edge-areas of the sample consistently reveal broad and narrow emissions, respectively. The measured optical properties of these defects and the associated ZPL peak shift and line broadening as a function of temperature between 77° and 300° K are qualitatively and quantitatively explained. Moreover, an enhancement of the photostable PL emission by at least a factor of ×3 is observed when our pristine h-BN was irradiated with a 532 nm laser.

Analyzing the Blood Bank Service Quality from Indian Blood Donors' Perspective: An Empirical Evidence.

OBJECTIVE: The objective of this study is to assess the levels of service quality provided by blood banks from blood donors' perspective and simultaneously judge the opinion of their satisfaction level based on SERVQUAL (service quality) variables, namely Reliability, Assurance, Tangibility, Empathy, and Responsiveness. MATERIALS AND METHODS: A self-administered and respecified structured SERVQUAL questionnaire is prepared to address expectation and perception of services experienced by blood donors. A total of 280 blood donors' responses were collected by visiting blood banks. RESULTS: The study endorsed all the significant five dimensions affecting the blood donors' expectation with actual service experienced during the exercise of donation. Average of overall service quality index gap is 0.38. Highest gap scores were significantly perceived in "Assurance" (Gap score 0.55) and "Empathy" (Gap score 0.49). In addition, "Tangibles," "Reliability," and "Responsiveness" scores are equitable, implying the blood donors' satisfaction level with the blood bank services. CONCLUSIONS: This study divulges blood bank's need to dissect and evaluate the level of service quality provided by them, along with consideration to the measurements of service quality gap models for the better fulfillment of blood contributors and retention.