An ITO (Indium Tin Oxide) coated window is a transparent conductive substrate that combines low sheet resistance with high optical transmittance. Due to this unique balance, ITO-coated windows are widely used in research and development, optoelectronics, and thin-film photovoltaic technologies.
ITO-coated glass substrates serve as transparent semiconductor oxide electrodes, making them essential in applications such as organic/inorganic heterojunction solar cells, Schottky solar cells, CdTe solar cells, and other thin-film photovoltaic devices.
What Is an ITO Coated Window?
ITO-coated windows belong to the family of Transparent Conductive Oxides (TCOs). The material is an N-type semiconductor, chemically represented as Sn:In₂O₃.
A uniform thin layer of ITO is deposited onto a glass substrate, resulting in:
- High electrical conductivity
- Excellent transparency in the visible spectrum
- Low surface (sheet) resistance
The coating process is typically carried out using magnetron sputtering under high vacuum at approximately 300 °C.
ITO Coating Structure & Manufacturing
- Substrate: Borosilicate glass or float glass (single-side polished)
- Coating type: Single-side ITO coating
- Conductive surface: ITO-coated side
- Insulated surface: Uncoated glass side
To enhance performance and durability, a silicon dioxide (SiO₂) passivation layer is introduced between the glass substrate and the ITO layer:
- SiO₂ thickness: ~25 nm
- Function: Improves adhesion, coating stability, and long-term reliability
Maximum operating temperature of an ITO-coated window is approximately 350 °C (662 °F).
Optical & Electrical Performance
Transmittance Spectrum
- Visible light transmittance at 550 nm: >85%
- Haze: <1%, ensuring excellent optical clarity
Electrical Properties
- Sheet resistance: 10–100 Ω/sq
- Conductivity: Inversely proportional to sheet resistance
- Work function: ~4.8–4.9 eV (after proper surface cleaning)
Film Characteristics
- ITO thickness: 50–200 nm (500–2000 Å)
- Surface roughness: 1–10 nm (depending on specification)
This balance between sheet resistance, transmittance, and layer thickness is critical in ITO window design and is tailored according to application needs.
Applications of ITO Coated Windows
ITO-coated windows are used across a wide range of industries, including:
- Digital microfluidic devices
- Display and optoelectronic devices
- Thin-film solar cell fabrication
- OLED and electroluminescent displays (ELD)
- LCD, plasma, and flat panel displays
- Camera systems and spectro-electrochemistry
- Photovoltaic cell manufacturing
- Switchable and smart windows
- EMF / EMI / EMC / RFI / HF shielding
- Transparent heaters and antistatic windows
- De-icing and defrosting coatings (aerospace)
- Flat antennas for mobile communication
- Biological devices and cell culture substrates
Precision ITO Windows from Shape Optics
Shape Optics provides high-quality, precision ITO-coated windows tailored for optical, electronic, and photovoltaic applications.
If you require custom sizes, thicknesses, sheet resistance, or optical specifications, our engineering team is ready to support your project.
Contact us today to discuss your customized ITO window requirements.