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The frequency upconversion emissions in the Er(3+)/Er(3+)-Yb(3+) doped/codoped hexagonal shaped La2O3 phosphor characterized by X-ray diffraction (XRD) upon excitation with 980 nm and 800 nm CW lasers have been investigated. The upconversion emissions corresponding to the (2)H(9/2) → (4)I(15/2), (2)H(11/2) → (4)I(15/2), (4)S(3/2) → (4)I(15/2) and (4)F(9/2) → (4)I(15/2) transitions peaking at 409 nm, 523 nm, 548 nm and 660 nm have been observed under 980 nm excitation whereas 523 nm, 548 nm and 660 nm upconversion emission bands have been visualized under 808 nm excitation. The upconversion emission intensity of Er(3+) ions is enhanced by several times due to the codoping with Yb(3+) ions, under 980 nm excitation while there is a reduction in intensity in the codoped sample under 808 nm excitation. The decay curve analysis for the green UC emission band corresponding to the (4)S(3/2) → (4)I(15/2) transition in the Er(3+)/Er(3+)-Yb(3+) doped/codoped La2O3 phosphor upon 980 nm excitation has been done. The colour coordinate of the phosphor sample has been calculated at different pump powers and its value is observed to be almost similar to that of the standard green colour and also independent of the excitation power density. The effect of temperature on the upconversion emission intensity of the green emissions has been determined and noted that the present phosphor material can be used in making temperature sensing device upto 600 K.

Ferroelectric BaTiO3 became a multifunctional material via doping of lanthanide ions (0.3 mol% Er(3+)/3.0 mol% Yb(3+)) and subsequently upconversion luminescence was enhanced by incorporation of Zn(2+) ions. Upconversion luminescence of BaTiO3:Er(3+)/Yb(3+) perovskite nanophosphor has been studied using 800 and 980 nm laser excitations. The emission dynamics is studied with respect to its dependence on input power and external temperature including lifetime. Based on time-resolved spectroscopy, it is inferred that two types of Er(3+) sites are present in the barium titanate lattice. The first one is a short lived component (minor species) present at 6-coordinated Ti-sites of low symmetry while the second one is a long lived component (major species), present at 12-coordinated Ba-sites with high symmetry. The influence of the introduction of Zn(2+) ions on the lifetime of (4)S3/2 and (4)F9/2 levels of Er(3+) ions is also investigated. Enhanced temperature sensing performance (120 K to 505 K) of the material is observed using the fluorescence intensity ratio technique, employing the emission from the thermally coupled, (2)H11/2 and (4)S3/2 energy levels of Er(3+) ions. The defect luminescence of the material is also found to increase upon Zn-doping.

The codoping effect of Zn(2+) ions on luminescence emission in visible and near infrared (NIR) regions of Y2O3:Ho(3+)-Yb(3+) phosphor prepared by low temperature combustion process have been investigated under 980 nm and 448 nm excitations. The phase and crystallite size of the prepared phosphor were determined by X-ray diffraction analysis and processes involved in the upconversion mechanism have been discussed in detail via pump power dependence, decay curve analysis and a suitable energy level diagram. The temperature sensing performance of the developed material has also been investigated by measuring the fluorescence intensity ratio of the blue upconversion emission bands centred at 465 nm and 491 nm up to 673 K. It is found that by using fluorescence intensity ratio technique, appreciable sensitivity for temperature measurement can be achieved from the present phosphor material, which indicates its applicability as a high temperature sensing probe. The fabrication of green LEDs using the developed phosphor material has also been suggested.

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Purpose It has been found that critical success factors (CSFs) are responsible for successful implementation of total quality management (TQM) system. The purpose of this paper is to make a comparative analysis of the importance of 20 TQM CSFs to the strategic choices of the firms such as innovators, prospectors, and defenders. Design/methodology/approach From extant literature review on TQM, 20 CSFs have been carried out. The empirical data for this study was drawn from a survey of 111 firms in India. One-way ANOVA approach has been applied for analysis. Findings The findings of the research show that the CSFs hold importance for different firm’s strategy. From these 20 CSFs, some CSFs may be critically important for all three types of firm, while others have their significant roles for innovators, prospectors, and defenders individually which are better prepared for TQM implementation. Practical implications The results of this study present the importance of knowing the appropriate CSFs to a strategy of the firms. The emphasis on CSFs will help organizations in accepting and rejecting TQM practices when they try to implement TQM and it is equally important in a global context. Apparently, it is evident that if there is a mismatch of strategy and CSFs with TQM practices it may interrupt the smooth operations of the company. Originality/value This research can be useful for those firms who are in the starting phase of TQM implementation with consideration of CSFs. Moreover, this research also attempts to inspire managers to consider the appropriate CSFs for implementing TQM effectively in their firms.

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