Engineering of Large Third-Order Nonlinearities in Atomic Layer Deposition Grown Nitrogen-Enriched TiO₂

Abstract

The third-order nonlinear optical properties of Nitrogen-enriched TiO2 films deposited by Atomic Layer Deposition (ALD) at a temperature between 100-300°C on quartz substrates were studied using thermally managed Z-scan technique. TiO2 oxide films prepared by Physical Vapor Deposition (PVD) at room temperature were used as control samples. The as-grown ALD films deposited at 150-300°C exhibited values for the nonlinear index of refraction, n2, between 0.6x10-11 and 1x10-9 cm 2 /W, which is 4-6 order larger than previously reported. Annealing the films, for 3 hours at 450°C in air, reduced the nonlinearities below the detection limit of the experimental setup. Similarly, as-grown 100°C ALD and PVD films did not produce a discernible Zscan trace. Composition analysis performed by x-ray photoelectrons spectroscopy (XPS) reveals the presence of Ti-ON metallic bonds in the films that showed high nonlinear optical response. The presence of the metallic bonding gives the films deposited on Si (100) a golden color. These results demonstrate the possibility of a new class of thin-film nonlinear materials that their properties can be tailored by controlling the film composition.

Impact of nonlocal response in plasmonic metasurfaces on four-wave mixing

“…Note that for the isotropic materials, Au or dielectrics, we have χ (3) = χ (3) xxxx = χ (3) yyyy = χ (3) zzzz = χ (3) xxyy + χ (3) xyxy + χ (3) xyyx , and χ (3) xxyy = χ (3) xyxy = χ (3) xyyx is assumed [41]. The nonlinear materials, such as SrTiO 3 films [42], nonstoichiometric SiC [43] or SiO x C y films [44], transition-metal oxides (Cr 2 O 3 , Mn 3 O 4 etc) [45], nitrogen-enriched TiO 2 films [46], Si quantum dots doped Si-rich SiN x films [47], P-toluene sulphonate [48], possess large χ (3) ∼ 10 −17 m 2 V −2 , and the component χ (3) iiii (i = x, y, z) is assumed to be 4 × 10 −18 m 2 V −2 [20].…”

Design of A-D-A-Type Organic Third-Order Nonlinear Optical Materials Based on Benzodithiophene: A DFT Study

“…With the rapid development of nonlinear optics, nonlinear optical (NLO) materials have been widely applied in the field of fiber optics [ 1 ], data transformation [ 2 ], photonic lasers, and data storage in the area of wireless communication [ 3 ]. At present, the design and synthesis of high-performance NLO materials in organic and inorganic systems still meet major challenges [ 4 ]. In recent decades, many materials exhibited good optical nonlinearity, including organic materials [ 5 , 6 , 7 , 8 ], perovskite quantum dots [ 9 ], nanoclusters [ 10 , 11 , 12 , 13 , 14 ], organic-inorganic hybrid materials [ 1 , 15 , 16 ], etc.…”

Large Third-Order Nonlinearities in Atomic Layer Deposition Grown Nitrogen-Enriched TiO2 Nanoscale Films

“…These materials have demonstrated 5 large third-order optical nonlinearities with fast response times (~picosecond time scale). In particular, we have shown 6 that atomic layer deposition (ALD) grown TiO2, a highly studied material for its applications in high-k dielectrics 7 and photoelectrochemical 8 processes, has a very large nonlinear index of refraction, n2.…”