Product Overview

Sapphire ITO coated substrate is a high-performance material consisting of a single-crystal sapphire (Al₂O₃) wafer coated with a transparent conductive Indium Tin Oxide (ITO) thin film.

This combination integrates:

• The exceptional mechanical strength and thermal stability of sapphire
• The excellent electrical conductivity and optical transparency of ITO

Compared with conventional glass-based ITO substrates, sapphire-based solutions provide superior durability, wider optical transmission range, and better performance in harsh environments, making them ideal for advanced optoelectronic applications.

Structure & Working Principle

ITO (Indium Tin Oxide) is a transparent conductive oxide (TCO) that enables both electrical conduction and light transmission.

The ITO layer is typically deposited onto the sapphire surface using:

• Magnetron sputtering
• Electron beam evaporation
• Pulsed laser deposition (PLD)

Working principle:

• The ITO coating forms a thin conductive layer
• Sapphire acts as a high-transparency, high-strength substrate
• Together, they function as a transparent electrode material

Key Features

• High optical transmittance: ≥85% (visible range)
• Low sheet resistance: 5–100 Ω/□
• Excellent thermal stability: suitable for high-temperature processes
• Outstanding hardness: Mohs 9 (scratch-resistant)
• Wide spectral transmission: UV to IR
• Strong coating adhesion and durability

Applications

Sapphire ITO coated substrates are widely used in:

• GaN-based LEDs (transparent electrodes)
• UV photodetectors and sensors
• Laser systems and optical windows
• High-temperature optoelectronic devices
• MEMS and microelectronic devices
• Specialized transparent conductive components

Typical Specifications

Manufacturing Process

1. Sapphire substrate polishing and cleaning
2. Vacuum deposition of ITO thin film
3. Thermal annealing (to optimize conductivity and transparency)
4. Optional photolithography and patterning
5. Final inspection and packaging

FAQ

Q1: What is the advantage of sapphire over glass for ITO coating?
A: Sapphire offers significantly higher hardness, better thermal resistance, and a wider optical transmission range, making it suitable for demanding environments.

Q2: How does ITO thickness affect performance?
A:

• Thicker ITO → lower resistance but reduced transparency
• Thinner ITO → higher transparency but increased resistance

Q3: Can patterned electrodes be fabricated?
A: Yes, customized patterns can be achieved through photolithography and etching processes.

Q4: Is double-side coating available?
A: Yes, both single-side and double-side ITO coatings can be provided based on application requirements.