The possibility of pulsed laser deposited organic thin films for light-emitting diodes

• Published in: Thin solid films Vol. 409; no. 1; pp. 37 - 42
• Main Authors: Hong, C., Chae, H.B., Lee, K.H., Ahn, S.K., Kim, C.K., Kim, T.W., Cho, N.I., Kim, S.O.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 22.04.2002; Elsevier Science
• Subjects: Alq 3; Applied sciences; Cross-disciplinary physics: materials science; rheology; Deposition technology; Electronics; Exact sciences and technology; Laser deposition; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Microelectronic fabrication (materials and surfaces technology); Organic film; Photoluminescence (PL); Physics; Pulsed laser deposition (PLD); Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; TPD; TPD; Photoluminescence (PL); Pulsed laser deposition (PLD); Organic film; Alq 3; Inorganic compounds; Aluminium complexes; Nitrogen heterocycle; Photoluminescence; Roughness; Pulsed lasers; Characterization; Thin films; Microelectronic fabrication; Chemical preparation; Bicyclic compound; Organic compounds; Organic ligand; Light emitting diodes; Amorphous state; Experimental study; Growth from vapor; Diamine; Alq3; Phenols; Benzenic compound; Ultraviolet visible spectrum; Laser ablation technique
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/S0040-6090(02)00100-1

Organic films of Alq 3 and TPD, which stand as successful materials used in organic electroluminescence applications, were deposited by the pulsed laser deposition method as an alternative to traditional thermal evaporation and spin coating techniques. An organic pellet target was ablated with two wavelengths, 532 and 355 nm, of a Q-switched Nd/YAG laser at a base pressure of 2×10 −5 torr. Films on slide glasses were evaluated by photoluminescence, AFM, absorption spectra, and XRD to find the possibility of those films acting as organic light-emitting diodes. When 355 nm laser irradiation was used for deposition, Alq 3 and TPD films had negligible voids and were less stressed than thermal films. Even though we used a highly stressed Alq 3 pellet target, the Alq 3 film prepared by pulsed laser deposition showed a preferential structure similar to the thermally evaporated Alq 3 film. Films deposited in this experiment were more amorphous than the films fabricated by excimer lasers.