Low-temperature technology and physical processes in green thin-film phosphor Zn₂GeO₄-Mn

Abstract

Thin-film Zn 2 GeO 4 :Mn phosphors with lower temperature of crystallization and potentially compatible with industrial technologies were investigated. The technology of thin films synthesis has been developed and their structure and crystal parameters have been investigated. Photoluminescence excitation spectra, photoconductivity, temperature dependencies and ESRspectra of manganese ions were studied. A mechanism for luminescence in this phosphor has been proposed. Results are presented of cathodo-and electro-luminescence of thin film structures of Zn 2 GeO 4 :Mn.

Mg1.96−1.96xZn1.96xGeO4:Mn0.04 phosphors for electroluminescent display applications

“…Also energy transfer mechanism is not so efficient as in the case of Zn 2 GeO 4 :Mn. In Zn 2 GeO 4 the mechanism of PL is identified as resonant energy transfer from a sub-band gap level, due to intrinsic defects, to Mn 2+ levels [18,28]. In Mg 2 GeO 4 also a sub-band gap level is observed as the Mn 2+ emission is triggered from a level which is nearly 1 eV low from its conduction band.…”

Effect of ZnO Buffer Layer on the Structural and Optical Properties of Zn[sub 2]GeO[sub 4]:Mn[sup 2+] Thin Films

“…Researchers around the world have been focusing on oxide phosphors 1,2 due to better stability in vacuum without corrosive gas emission under electron bombardment when compared to sulfides. Several binary and ternary oxide phosphors, such as Y 2 O 3 , 3 Ga 2 O 3 , 4,5 ZnGa 2 O 4 , [6][7][8][9][10] Zn 2 GeO 4 , [11][12][13][14][15][16][17][18] and Mg 2 GeO 4 , 19 etc. have been extensively studied in bulk powder as well as in thin-film form.…”

“…17 Mn 2+ substitutes for Zn 2+ in the host and a green emission is obtained via a transition between 4 T 1 -6 A 1 levels of Mn 2+ . Thin films of Zn 2 GeO 4 have been deposited using pulsed laser deposition, 11 radio frequency ͑rf͒ magnetron sputtering, [12][13][14] etc. and they find application as cathodoluminescent ͑CL͒ phosphor and electroluminescent ͑EL͒ phosphor.…”

“…Thick dielectric EL and alternating current thin-film electroluminescent ͑TFEL͒ devices with Zn 2 GeO 4 as active layer has also been developed. 14,15 This phosphor has also been investigated for integrated optics applications. 18 Unfortunately, one of the fundamental problems of oxide thinfilm phosphors is their inferior luminous efficiency and brightness when compared to their powder form.…”

“…[20][21][22] In most studies postdeposition annealing ͓rapid thermal annealing ͑RTA͒, hydrothermal or furnace anneal͔ is carried out to improve the luminescent ͓photoluminescent ͑PL͒, EL, or CL͔ characteristics of the phosphor layer. [11][12][13][14][15] The high crystallization temperature of oxide phosphors also prevents them from being deposited on cheaper glass substrates. Thick dielectric substrates like BaTiO 3 and high-temperature postdeposition annealing is usually employed to improve the crystalline quality of the thin film.…”