1. Characteristics

1) Chemical composition and structure

 ・The main component is TeO (tellurium oxide), which may contain TeO₂ (tellurium dioxide) or non-stoichiometric compounds.

 ・The crystal structure is usually amorphous or low crystalline, suitable for the preparation of homogeneous thin films.

2) Optical properties

・High refractive index (n≈2.0-2.5), suitable for optical coatings with high refractive index.

・Wide light transmission range (visible to mid-infrared region), suitable for use in infrared optical devices.

・Photosensitivity

Structural change can occur upon UV irradiation, suitable for photoresists and optical storage materials.

3) Electrical properties

・Conductive properties (forbidden bandwidth ~3.5eV), can be used for transparent semiconductor films.

・Resistance is adjustable.

Conductivity can be optimized by adding Sb, Bi, etc.

4) Thermal stability

・Low melting point (TeO₂ melting point ~733°C), suitable for low-temperature deposition processes (e.g., thermal deposition, sputtering).

5) Mechanical and chemical stability

・Brittle, requiring optimization of the target sintering process to improve strength.

Chemically stable at room temperature, but soluble in strong acids and bases.

2. Main applications

1) Optical coatings

・High refractive index coatings

Used for camera lenses, laser mirrors, and optical fiber communication devices.

・Infrared window materials

Infrared detectors, infrared camera optics.

2) Optoelectronic devices

・Optical waveguides

Making integrated optical devices by using high refractive index.

・Optical storage device

Rewritable optical discs (DVD-RW, etc.) using the photosensitivity of TeO.

3) Semiconductors and sensors

・Transparent Conductive Oxide(TCO)

For electrodes of flexible displays and solar cells.

・Gas sensors

Sensitive to gases such as NOx and H₂S for environmental monitoring.

4) Functional Glass and Smart Materials

・Chalcogenide glass

Used for infrared lenses and optical switches.

・Phase change memory (PCM): Combined with GeSbTe (GST) materials, used for high-speed storage devices.

5) Catalytic action and new energy

・Photocatalysis: decomposition of organic pollutants by ultraviolet light.

・Thermoelectric materials: Optimized materials for waste heat generation.