Slot-Die Nanoparticle Deposition – How Does it Work?

There are many different approaches to nanoparticle deposition on surfaces, from spin coating and dip coating to chemical vapor deposition and straightforward solvent evaporation. All of these have their advantages and disadvantages and the best deposition technique for an application largely depends on the quality of the film required and compatibility of the nanoparticle solution with the deposition technique.

Introducing Slot-Die Nanoparticle Deposition

Of these techniques, slot-die nanoparticle deposition is a versatile strategy that can be very carefully controlled to create incredibly uniform films even over large areas. Slot-die nanoparticle deposition works by passing a solution through a slot die head that is placed close to the substrate of interest. A roller is used to translate the substrate so that different areas of the substrate are coated as this can be continually moved. This is one reason why slot-die nanoparticle deposition can achieve such large area coverage.

A metering system is used to control the rate of flow of the solution through the slot die head and adjustments to the slit width or head dimensions can control the stability of the beads of solution that are formed. As all of these components can be mounted on translation stages, there can be precise control of head-surface distances and solution flow rates can be optimized for the best film quality. Controlling the flow rate in slot-die nanoparticle deposition is imperative for achieving uniform film thickness, as there is a direct relation between this and the thickness of the resulting film.

While the large number of variables in the slot-die nanoparticle deposition process means that finding optimum conditions can take some time, it is an excellent technique for nanoparticle deposition on both a small and industrial scale. Once flow rates and die dimensions are optimized, it is relatively straightforward to scale up processing to create much larger, homogenous films.

Nanoparticle Solutions for Slot-Die Coating

The compatibility of slot-die printing with many types of chemicals, including nanoparticle dispersions, has resulted in slot-die printing now being used to create printed electrochemical devices based on nanomaterials, including solar cells. This implies that it is possible to print device roll-to-roll, allowing for rapid commercialization of emerging technologies. For perovskite solar cells, one of the most promising candidates for solar cell technologies in terms of the year-on-year efficiency improvements, slot-die nanoparticle deposition means that transparent conductive oxide layers, formed from nanoparticles, can be created cheaply and efficiently, as well as the perovskite layers themselves.

The scalability and tunability of the slot-die nanoparticle deposition process for creating thin films of nanometer to micrometer thickness makes it an excellent and versatile technique for the creation of new electronic devices. All of Avantama’s nanoparticle solutions are compatible with slot-die processing.

Avantama’s expertise in creating nanoparticle solutions and custom formulations make it possible to rapidly prototype new ideas and device with slot-die nanoparticle deposition that can then be rapidly scaled up to commercial levels.  There does not need to be any change in the formulation of the nanoparticles for scaling up and Avantama have extensive experience in both cutting-edge research developments in nanoparticle deposition for electronic applications and bringing those ideas to market rapidly.