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Manipulating optical and electrical properties is promising for applications such as photodetectors and solar cells. Comparing with chemical preparation methods, tuning optical and optoelectronic properties by physical vapor phase methods has extra merits such as large area uniformity and CMOS compatibility. An in situ oxygen ion beam preparation method with an ion beam modulation is demonstrated for lead selenide. Polycrystalline lead selenide thin films with tunable optical band gap and low structural disorder have been fabricated using an orthogonal experimental scheme. The morphological evolution between three specific microstructures, mainly governed by ion energy and annealing temperature, has been observed. The structural characterizations indicate the presence of some oxides phases and crystallite size of hundreds of nanometers. The more suitable optical band gap within 0.75–1.1 eV was obtained at room temperature for absorption of mid-infrared photons. The ultra-low Urbach energies suggest a structurally well-ordered microstructure. The dependences of the structural, electrical and optical properties on the preparation parameters have been revealed by range analysis, indicating the main role of ion energy in the manipulations of these properties. Ion energy and beam current were revealed to be more sensitive in affecting optoelectronic properties, and the manipulation effects were demonstrated to be long wavelength sensitive. These results provide an attractive approach to manipulate and optimize the structural, electrical and optical properties of polycrystalline lead chalcogenides in mid-infrared optics and optoelectronics. Image 1 • An in-situ O+ beam preparation and modulation method for polycrystalline PbSe was demonstrated. • Three types of special microstructures were induced by interaction with ion beam. • The optical bandgap was successfully adjusted to be more suitable for detecting mid-infrared photons. • A structurally well-ordered microstructure with sharp Urbach slope was obtained. • Range analysis revealed that the ion energy plays the main role in manipulating the optical properties. [ABSTRACT FROM AUTHOR]

For achieving more functionalities of perovskite manganese oxides film, an epitaxial La 0.8 Sr 0.2 MnO 3 (LSMO) film was deposited on a flexible substrate (mica) by pulsed laser deposition. The film shows a paramagnetic-ferromagnetic (PM-FM) phase transition at 134 K together with metal-insulator transition (MIT) at 149 K. The measurement of hysteresis loop indicates that the easy-magnetization axis lied in film plane. The transport behavior can be fitted well with the small polaron model, giving out the activation energy E hop = 176.9 meV. Different from the common anisotropic magnetoresistance (AMR) in manganite film, an isotropic magnetoresistance (IMR) effect was observed in LSMO film and the relatively small thickness of LSMO film (∼ 50 nm) is a major reason for it. After the cyclic flexural bending for 1.0 × 104 times, we found the magnetic properties of LSMO film were improved. Micromagnetic detection shows that the activation energy for polaron hopping (E a = 144.7 meV) remarkably decreases by the cyclic flexural bending process. We suggested that the inhomogeneous/incompact part located at the zone of neighbouring domains become uniform and tight after circulating bending, which facilitates the rotation of domains and the polarons hopping so that the magnetic and electronic performance are enhanced. • A flexible pervoskite manganite film has been fabricated by PLD. • The film shows an exchanged polaron interactions in transport behavior. • An isotropic magnetoresistance effect was observed in film. • The magnetization and electronic transport property have been promoted after the cycling bending. [ABSTRACT FROM AUTHOR]

The composition dependent magnetic structure in epitaxial BaFe 12-x Sc x O 19 (0 ≤ x ≤ 2.1, BaScM) thin films have been investigated. Results show that with increasing Sc3+ content, the out-of-plane c -axis lattice constants of BaScM films increase but do not follow the Vegard's law. The changes in hysteresis loops indicate a variation of magneto-crystalline anisotropy from the uniaxial-type for BaFe 12 O 19 to the near-planar type for BaFe 10.2 Sc 1.8 O 19. The remanent magnetic domains change from a mixture of dots and maze-like structure to more maze-like structure as the Sc3+ content increases. The above magnetic results can be explained by a composition dependent magnetic structure transition from collinear-type ferrimagnetic magnetic structure to the non-collinear conical magnetic structure which appears at Sc3+ content x ≥ 0.6. The ZFC/FC curves further show that the conical magnetic structure transition temperature (T cone) of the films increases with the Sc3+ content until x ≥ 2.1. The above results may help better apply BaScM films in the electromagnetic devices. • With increasing Sc3+ content, lattice constant c increases but doesn't follow the Vegard's law. • With increasing Sc3+ content, magnetocrystalline anisotropy of the film changes from uniaxial-type for to conical-type. • With increasing Sc3+ content, magnetic domains change from a mixture of dots and maze structure to more maze-like structure. • The conical magnetic structure transition temperature (T cone) increases with the Sc3+ content until x ≥ 2.1. [ABSTRACT FROM AUTHOR]

Tuning the optical and optoelectronic properties of materials is attractive for solar energy and infrared sensing applications. Here, we proposed an ion beam co-growth preparation method that can continuously tune the optical band gap and absorption and thus optoelectronic properties of lead selenide. The optical band gap of the material can be effectively tuned by ion energy and beam current, varying continuously from 0.79 to 1.03 eV. The tuning mechanism of ion beam on optical and optoelectronic properties was revealed by orthogonal range analysis. The results of range analysis on optical properties show that ion energy and beam current play the key role in adjusting the optical band gap and absorptivity. Ion beam regulation also reduces the Urbach energy of the material, suggesting low thermal disorder and structural defects of the resulting material. The photoresponsivity and specific detectivity of thin film devices can also be effectively tuned by the ion energy and beam current. The material is sensitive to mid-infrared radiation, and the preliminary photoresponsivity is up to 0.61 A/W at 3 µm, which is better than those of traditional thermal diffusion in oxygen atmosphere. [Display omitted] • An ion beam co-growth preparation was demonstrated for tuning optical and optoelectronic properties. • Tunable optical bandgap was induced by low energy ion beam from 0.79 to 1.03 eV. • The resulting material is IR photo-sensitive with responsivity up to 0.61 A/W at 3 µm. • The Tuning mechanisms of low energy ion beam on optical and optoelectronic properties were revealed. [ABSTRACT FROM AUTHOR]

Tuning the optical and optoelectronic properties of materials is attractive for solar energy and infrared sensing applications. Here, we proposed an ion beam co-growth preparation method that can continuously tune the optical band gap and absorption and thus optoelectronic properties of lead selenide. The optical band gap of the material can be effectively tuned by ion energy and beam current, varying continuously from 0.79 to 1.03 eV. The tuning mechanism of ion beam on optical and optoelectronic properties was revealed by orthogonal range analysis. The results of range analysis on optical properties show that ion energy and beam current play the key role in adjusting the optical band gap and absorptivity. Ion beam regulation also reduces the Urbach energy of the material, suggesting low thermal disorder and structural defects of the resulting material. The photoresponsivity and specific detectivity of thin film devices can also be effectively tuned by the ion energy and beam current. The material is sensitive to mid-infrared radiation, and the preliminary photoresponsivity is up to 0.61 A/W at 3 µm, which is better than those of traditional thermal diffusion in oxygen atmosphere. [Display omitted] • An ion beam co-growth preparation was demonstrated for tuning optical and optoelectronic properties. • Tunable optical bandgap was induced by low energy ion beam from 0.79 to 1.03 eV. • The resulting material is IR photo-sensitive with responsivity up to 0.61 A/W at 3 µm. • The Tuning mechanisms of low energy ion beam on optical and optoelectronic properties were revealed. [ABSTRACT FROM AUTHOR]