Rare earth complex dopants in a.c. thin-film electroluminescent cells

• Published in: Journal of luminescence Vol. 23; no. 1; pp. 175 - 190
• Main Authors: Benoit, J., Benalloul, P., Blanzat, B.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.1981
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/0022-2313(81)90196-4

The authors have carried out some comparative studies between the different dopants used in thin-film a.c. electroluminescent devices; as well as the Mn 2+ ion leading to high luminosity and long-lived devices, the use of trivalent rare earth ions (Ln 3+ and rare earth fluoride centers LnF 3 (lumocen center) has been investigated. In the first part the author explain the nature of LnF 3 centers and they have shown that these centers are a new type of luminescent center, which are strongly linked to the ZnS matrix: the authors propose labeling these centers “complex centers”. In the second part they have searched for other promising centers and have chosen the rare earth oxysulphides Y 2O 2S (Ln) and La 2O 2S (Ln). These compounds have been introduced as complex centers in the ZnS matrix by RF sputtering methods. Using the following trivalent ions: Tm 3+, Tb 3+, Eu 3+, the authors have realized some devices emitting respectively the three basic colours (blue, green, red). The authors have presented some properties of these centers.