Radiation Effects & Defects in Solids Vol. 162, Nos. 10–11, September–October 2007, 723–729 Photoluminescent characteristics of hafnium oxide layers activated with trivalent terbium (HfO 2 :Tb +3 ) J. GUZMÁN-MENDOZA†, D. ALBARRÁN-ARREGUÍN†, O. ALVAREZ-FRAGOSO*†, M. A. ALVAREZ-PEREZ†, C. FALCONY‡ and M. GARCÍA-HIPÓLITO† †Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, A.P. 70-360, Coyoacán 04510, México, D.F., Mexico ‡Departamento de Física, CINVESTAV-IPN,Apdo. Postal 14-740, 07000 México D.F., Mexico (Received 1 September 2006; revised 17 November 2006; in final form 13 March 2007) Hafnium oxide layers doped with trivalent terbium ions have been synthesized using the ultrasonic spray pyrolysis technique. Photoluminescence properties were studied as a function of growth param- eters such as the substrate temperature and the terbium concentration. The films were grown starting from aqueous solution of Hafnium and Terbium chlorides. The results show that crystalline structure of HfO 2 :Tb +3 films depends on the temperature. Emission and excitation spectra were obtained for the HfO 2 :Tb +3 films using 262 nm as the excitation wavelength. All emission spectra show bands centered at 488, 542, 584 and 621 nm, which correspond to the electronic transitions: 5 D 4 → 7 F j (j = 3,..., 6) characteristic of trivalent terbium ion. The dominant emission intensity corresponds to the green color, which depend on the terbium concentration incorporated inside the host matrix. Keywords: Photoluminescence; Spray pyrolysis; Photoluminescence hafnium oxide coatings 1. Introduction In recent years, many investigations have been dedicated to hafnium oxide (HfO 2 ) compound due to its chemical and physical properties. Hafnium oxide is a high refractive index material with a wide band gap (5.68 eV) [1]. Its transparency is extended over a wide spectral range, from the ultraviolet to the mid-infrared [2]. As a result, hafnium oxide is widely used in optical coating applications [3, 4]. Furthermore, HfO 2 can be used as protective coating due to its thermal stability and hardness. In microelectronics, HfO 2 has recently received considerable attention as an alternative material for silicon oxide for its use as a high-k gate dielectric layer in metal oxide-semiconductor devices of the next generation [5, 6]. Many techniques are used to prepare hafnium oxide films; these include atomic layer depo- sition [8, 9] electron beam evaporation [7, 10], ion-assisted electron beam deposition [11, 12], chemical vapor deposition [13] and sol-gel [14]. However, the ultrasonic spray pyrolysis has *Corresponding author. Tel.: +52-55-56-22-46-49; Fax: +52–55-56-16-13-71; Email: oaf@servidor.unam.mx Radiation Effects & Defects in Solids ISSN 1042-0150 print/ISSN 1029-4953 online © 2007 Taylor & Francis http://www.tandf.co.uk/journals DOI: 10.1080/10420150701482519