Volatile Metal β‐Diketonates: ALE and CVD precursors for electroluminescent device thin films

Abstract

The use of volatile P-diketonate chelates as precursors for the deposition of thin films for electroluminescent devices is reviewed. Alternating current thin film electroluminescent (ACTFEL) devices consist of an emitting layer sandwiched between two dielectric layers, together with conducting and buffer layers. Besides various physical deposition techniques, the commonly applied methods for preparing thin films are chemical vapor deposition (CVD) and its particular variant atomic layer epitaxy (ALE). Alkaline earth P-diketonates are used as precursors for deposition of the semiconducting alkaline earth sulfide and thiogallate films that provide the matrix in emissive layers, while P-diketonates of lanthanides and a few other metals (Mn, Na, K) are precursors for dopants and codopants producing colors. P-Diketonate precursors can also be used for the preparation of dielectric alkaline earth titanate and oxide layers. Current research on thin film electroluminescent materials is focused on improving the blue color produced by cerium doping of alkaline earth sulfide and thiogallate matrices. The synthesis and properties of P-diketonate chelates and the growth and characterization of the thin films obtained with them are presented and discussed. This review of precursors for TFEL materials is also relevant for other materials, including oxide superconductors.

Tris(2,4‐pentanedionato)scandium(III) as a Precursor for Plasma‐Assisted Liquid Injection CVD to Deposit Nanocrystalline Scandia Thin Films

“…However, organometallic compounds are air-sensitive and therefore more difficult to synthesize and handle. The volatile b-diketonate chelates are used as precursors for the deposition of thin films for electroluminescent devices, [26] binary rare earth oxides, fluorides, high temperature superconductors, dielectric layers, and protective coatings. [27] DOI: 10.1002/cvde.200906792…”

High Growth Rate of Erbium Oxide Thin Films in Atomic Layer Deposition from (CpMe)3Er and Water Precursors

“…[25,26] In addition, we have previously reported the ALD of erbium oxide using Er(thd) 3 (thd = 2,2,6,6-tetra-methyl-3,5-heptane-dione) and ozone as precursors. [27,28] b-Diketonate-type thd-complexes are volatile, and have frequently been utilized as precursors in ALD, [29] for example in the case of Sc 2 O 3 , [30] Y 2 O 3 , [31,32] La 2 O 3 , [33] CeO 2 , [34,35] as well as other Ln 2 O 3 films (Ln = Nd, Sm, Eu, Gd, Dy, Ho, Tm). [4,28,36] b-Diketonates do not readily react with water, but require the use of a stronger oxidizer, such as ozone, to produce oxide thin films with low carbon and hydrogen content.…”

Novel Low Melting Point Barium and Strontium Precursors for the MOCVD Growth of Barium‐Strontium‐Titanate Films

“…It is commonly accepted that AEE compounds based on b-diketonates are most suitable precursors for MOCVD, [23] the prominent representatives among them being the coordinatively saturated, mixed-ligand complexes [27] In such a way, the…”