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We report a significant enhancement in the thermoelectric figure-of-merit of phosphorous doped nanostructured n-type Si80Ge20 alloys, which were synthesized employing high energy ball milling followed by rapid-heating using spark plasma sintering. The rapid-heating rates, used in spark plasma sintering, allow the achievement of near-theoretical density in the sintered alloys, while retaining the nanostructural features introduced by ball-milling. The nanostructured alloys display a low thermal conductivity (2.3 W/mK) and a high value of Seebeck coefficient (−290 μV/K) resulting in a significant enhancement in ZT to about 1.5 at 900 °C, which is so far the highest reported value for n-type Si80Ge20 alloys.

Single-phase cool white-light emitting BaNb 2 O 6 :Dy 3+ phosphors have been synthesized via a conventional solid-state reaction method and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) observations and spectrofluorophotometric measurements. XRD and Rietveld structural refinement studies confirm that all the samples exhibit pure orthorhombic structure [space group -

Trivalent dysprosium (Dy3+)‐doped NaCaPO4 phosphors were synthesized by using a conventional solid‐state reaction technique. The phase and the structure of the as‐prepared powders were characterized by using X‐ray diffraction analysis and revealed that the pure NaCaPO4 formed with orthorhombic structure. The photoluminescence excitation and emission spectra were measured to characterize the luminescent properties of NaCaPO4:Dy3+ phosphors. Sharp emission peaks were observed at 482 nm (blue) and 575 nm (yellow) upon 367 nm excitation, which are attributed to the characteristic 4F9/2→6HJ (J=15/2 and 13/2) transitions of trivalent Dy3+ ions, respectively. The suitable control of the blue/yellow intensity ratio is expected to realize a white luminescent system. The lifetime of 4F9/2 level was measured by exciting Dy3+ ions at 355 nm excitation. The chromaticity coordinates were calculated from the emission spectra and analyzed with Commission International de I'Eclairage (CIE) programs and diagrams. The CIE color coordinates fall in the white light region under different ultraviolet (UV) excitations. These results indicate that NaCaPO4:Dy3+ phosphor could be a potential candidate for UV‐based white light‐emitting diodes.