Luminescence behaviour and deposition of Sc2O3 thin films from scandium(III) acetylacetonate at ambient pressure

Abstract

Scandium(III) oxide thin film deposition has been historically difficult to achieve without the use of vacuum-based or wet chemical systems due to precursor limitations of low vapour pressure or ambient instability. In this letter, the adoption of aerosol-assisted delivery of scandium(III) acetylacetonate has enabled the chemical vapour deposition of polycrystalline and amorphous Sc2O3 thin films at ambient pressure with high growth rates (ca. 500 nm h−1). The scandia films were intrinsically highly photoluminescent, exhibiting broad emission bands centred at 3.6 and 3.0 eV, which increased significantly in intensity upon aerobic annealing, accompanying a transition from amorphous to crystalline, while bands appearing at 2.1 and 2.3 eV seemed to occur only in the crystalline films. In addition, both amorphous and crystalline scandia films exhibited blue-green vibronic fine structure between 2.3 and 3.2 eV attributed to the electronic transition BΣ+→ΧΣ+22 in surface ⋯O−⋯O−Sc=O groups and split by a vibrational mode observed at 920±60 cm−1 by infrared spectroscopy. Band gaps of amorphous and crystalline Sc2O3 were determined to be 5.3 and 5.7 eV, respectively via diffuse reflectance. All films had high refractive indices, varying between 1.8 and 2.0 at 400 nm depending on film thickness and carrier gas used in the deposition; film thicknesses less than ca. 300 nm were observed to have a strong influence on the refractive index measured, while there was little variation for films thicker than this. The synthesis process itself is exceedingly low-cost and facile thus promising streamlined industrial scalability.

Effect of Annealing on Optical, Mechanical, Electrical Properties and Structure of Scandium Oxide Films

“…According to XRD data, only cubic Sc 2 O 3 phase (c‐Sc 2 O 3 ) was observed. The preferred orientation was (222), that is a typical value for Sc 2 O 3 films …”

“…Sc 2 O 3 is also commonly used for high‐power laser applications . Moreover, these films exhibit strong photoluminescent character under UV irradiation . In addition, Sc 2 O 3 can be used as the gate oxide material and surface passivation due to its high dielectric permittivity and chemical stability.…”

Energy Conversion Efficiency Enhancement of Polyethylene Glycol and a SiO2 Composite Doped with Ni, Co, Zn, and Sc Oxides

“… 10 , 12 Sc 2 O 3 exhibits strong photoluminescent properties with broad-band luminescence when exposed to UV light. 13 ZnO and Sc 2 O 3 were combined with a SiO 2 matrix to form new PEG/Zn-SiO 2 and PEG/Zn-SiO 2 composites with enhanced full-band light-driven reversible phase transitions.…”

Reflective Silver Thin Film Electrodes from Commercial Silver(I) Triflate via Aerosol-Assisted Chemical Vapor Deposition

“…15,16 It follows that AACVD enables a safer and wider selection of precursors, without many of the inherent hazards associated with thermal CVD precursors such as being corrosive, explosive, highly flammable or posing a risk to human health via inhalation. 14,17,18 AACVD has thus enabled the deposition of a range of films of metallic, 9,10 polymeric 19,20 and metal-oxide [21][22][23] compositions. Until now, AACVD of silver films has largely been led by Molloy et al, [24][25][26] having been achieved by an exhaustive process of precursor preparation, with mixed results with regard to film contamination, conductivity and reflectivity.…”

“…Aerosol-assisted chemical vapor deposition (AACVD) is an atmospheric-pressure alternative to thermal APCVD, which avoids the requirement of thermal APCVD that precursors should be appreciably volatile by instead generating an aerosol from a solution of the precursor. , It follows that AACVD enables a safer and wider selection of precursors, without many of the inherent hazards associated with thermal CVD precursors such as being corrosive, explosive, highly flammable, or posing a risk to human health via inhalation. ,, AACVD has thus enabled the deposition of a range of films of metallic, , polymeric, , and metal-oxide − compositions. Until now, AACVD of silver films has largely been led by Molloy et al, − having been achieved by an exhaustive process of precursor preparation, with mixed results with regard to film contamination, conductivity, and reflectivity.…”