Enhanced Emission and Improved Crystallinity of $$ {\hbox{KY}}_{3} {\hbox{F}}_{10} :{\hbox{Ho}}^{3 + } $$ KY 3 F 10 : Ho 3 + Thin Films Grown at High Deposition Temperature Using Pulsed Laser Deposition Technique

• Published in: Journal of electronic materials 2018-05, Vol.47 (5), p.2617-2624
• Main Authors: Debelo, Nebiyu G., Dejene, F. B., Roro, Kitessa, Senbeta, Teshome, Mesfin, Belayneh, Abebe, Tamirat, Mostert, L.
• Format: Article
• Language: English
• Subjects: Crystal structure; Crystallinity; Emission spectra; Excitation; Excitation spectra; Holmium; Lasers; Luminescence; Materials research; Neodymium lasers; Optical properties; Photoluminescence; Pulsed laser deposition; Semiconductor lasers; Silicon substrates; Temperature; Thin films; Wavelengths; YAG lasers
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-018-6089-9

The effect of substrate temperature on the structural, morphological, and luminescence properties of thin films prepared from a commercially available KY3F10:Ho3+ phosphor powder is investigated. The thin films were grown on silicon substrate at different substrate temperatures, ranging between 50°C and 600°C, by the pulsed laser deposition method using Nd-YAG laser radiation of wavelength 266 nm. The x-ray diffraction spectra show that the crystallinity of the films is significantly improved with an increment of substrate temperature with the calculated average crystallite size between 39 nm and 74 nm. The photoluminescence (PL) spectra also show enhanced emission at high deposition temperature. Green PL emission at 540 nm and faint red emission at 750 nm are observed from the PL spectra at excitation wavelengths of 362 nm, 416 nm, and 454 nm. The green emission is ascribed to the 5F4–5I8 and 5S2–5I8 transitions of Ho3+ and the faint red emission is due to 5F4–5I7 and 5S2–5I7 transitions of Ho3+. The peaks of the PL emission are found to increase with an increase in substrate temperature for all excitation wavelengths. For all the prepared films, the highest PL intensity occurs at an excitation of 454 nm.