Indium tin oxide and transparent conductive oxide
Liquid crystal displays, organic light-emitting diode variations, and the vast majority of flat panel display technologies all rely on transparent conductive oxides (TCO) to transmit current and act as the anode for each light-emitting element. As with any thin-film process, it is crucial to understand the thickness of each layer of material that makes up the display. For liquid crystal displays, methods for measuring the thickness of polyimide and liquid crystal layers are required. For organic light-emitting diodes, the thickness of the light-emitting, electrical injection and packaging layers needs to be measured.
When measuring any multiple layers, optical techniques such as spectral reflectance and ellipsometers need to measure or model to estimate the thickness and optical constants (reflectance and k value) of each layer.
Unfortunately, the properties that make indium tin oxide and other transparent conductive oxides useful in displays also make these thin film layers difficult to measure and model, thus making it hard to measure any substance on top of them.
Filmetrics' indium tin oxide solution
Filmetrics has developed a simple, feasible and cost-effective method to precisely measure indium tin oxide using spectral reflectance. By combining the novel indium tin oxide mode with F20-EXR, which has a very wide wavelength range of 400-1700nm, reliable "one-click" analysis of indium tin oxide is achieved. Once the characteristics of the indium tin oxide layer are determined, the key to the analysis of the remaining display layer is resolved.
Whether you are involved in fundamental research or manufacturing of displays, Filmetrics can provide you with what you need...
Measure the liquid crystal layer
- Polyimide, hard coating, liquid crystal, gap
Measure the organic light-emitting diode layer
- Luminescence, electrical injection, buffer pad, packaging
For blank samples, we recommend using the F20 series instruments. For finished films, the F40 and F42 product series have extensive applications.
Measurement example
In this case, we successfully measured the thickness of indium tin oxide films on sapphire and borosilicate glass substrates. The F10-RTA-EXR instrument, combined with Filmetrics' proprietary ITO diffusion model, can easily simultaneously measure transmittance and reflectance within the range of 380 nanometers to 1700 nanometers to determine thickness, refractive index, and extinction coefficient. Due to the unusual diffusion of ITO films on various substrates, this extended wavelength range is necessary.
Measurement Settings
