Growth optimisation of ZnS:Mn thin film phosphors for high intensity miniature electroluminescent displays

Abstract

This paper details an investigation into the deposition by RF magnetron sputtering of thin film phosphors specifically for use in laterally emitting thin film electroluminescent (EL) devices. The work presented here is concerned with the use of co-sputtering to optimise luminous efficiency and the use of transient (decay time) measurements to quantify the luminescent quality of the films. Thin films of phosphor were deposited by radio frequency RF magnetron sputtering in a custom built four electrode cluster deposition system. 800 nm films of ZnS:Mn were simultaneously cosputtered from ZnS and ZnS:Mn(l wt.%) solid targets. The thin films were deposited at different manganese concentrations by varying the RF power applied to each target.The films were deposited directly onto 100 mm diameter (100) n-type silicon substrates, or onto a layer of 300 nm of Y 2 03to fabricate electroluminescent test devices. Luminescence was characterised via photoluminescent excitation using a 337 nm pulsed N2 laser, with the PL optimum obtained at 0.38 ZnS:Mn power ratio.

Hydrothermal Synthesis of Nanoclusters of ZnS Comprised on Nanowires

“…Among II-VI compound semiconductors, zinc sulphide (ZnS) is well known due to its wide band gap of 3.7 eV at room temperature and high exciton binding energy of 40 meV. ZnS is used widely in various applications such as ultraviolet light emitting diodes [ 1 ], electroluminescence devices [ 2 ], infrared windows [ 3 ], and flat panel displays [ 4 ]. Recently, extensive efforts have been taken for the synthesis of various ZnS morphologies such as nanoparticles [ 5 ], nanorods [ 6 ], nanobelts [ 7 , 8 ], nanotubes [ 9 ], nanosheets [ 10 ], well aligned tetrapods [ 11 ], nanowires bundles [ 12 , 13 ], and hollow spheres [ 14 , 15 , 16 , 17 ].…”

Laser-induced doping and fine patterning of massively prepared luminescent ZnS nanospheres

“…This emission has been well documented in Mn-doped ZnS nanostructures. [28][29][30][51][52][53] It is assigned to the 4 T 1 / 6 A 1 transition of 3d 5 electrons conguration of the divalent manganese ion (Mn 2+ ) as illustrated in the schematic energy band diagram given in Fig. 4f.…”

Optical and photoelectric properties of Mn-doped ZnS thin film on a flexible indium-tin-oxide/polyethylene terephthalate substrate prepared by pulsed laser deposition

“…ZnS is a wide bandgap compound semiconductor with high transmittance in the visible range, and thus it is useful in a wide range of applications, including displays, solar cells, sensors, and photocatalysts [4][5][6][7][8][9][10]. So far, a number of research groups have fabricated ZnS thin films using a variety of techniques and have investigated their electro-optical properties [11][12][13][14][15][16][17][18][19][20].…”