Spectroscopic and photoluminescence properties of MgO:Cr3+ nanosheets for WLEDs

• Magnesium oxide (MgO) is an excellent wide band gap insulator.
• MgO:Cr3+ nanosheets were prepared via facile solution combustion method.
• Structural and PL of MgO:Cr3+ nanosheets were studied.
• CIE chromaticity co-ordinates fall in the white region.

This work explores the synthesis of nanocrystalline MgO:Cr3+ (1–9 mol%) nanophosphors via solution combustion route at 400 °C. The nanophosphors were well characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infra-Red (FTIR) spectroscopy. PXRD results confirm cubic phase and SEM micrographs indicate that the particles are highly porous and agglomerated. The TEM images show that the powder consists of spherical particles of size ∼5–15 nm. Upon 356 nm excitation the emission profile of MgO:Cr3+ exhibits an emission peak at 677 nm due to 2Eg → 4A2g transition. It was observed that PL intensity increases with increase in Cr3+ concentration and highest PL intensity was observed for 3 mol% doped sample and afterward it decreases, attributed to concentration quenching. The resultant CIE chromaticity co-ordinates in the white region make the present phosphor highly useful for display applications and also for white light-emitting diodes (WLEDs).

CIE and CCT of MgO:Cr3+Figure optionsDownload high-quality image (106 K)Download as PowerPoint slide