Atomic Layer Deposition (ALD) Used to Create Ultrablack Coating Perfect for Viewing the Cosmos

Researchers from the University of Shanghai for Science and Technology and the Chinese Academy of Sciences achieved a major milestone after successfully using a new method of Atomic Layer Deposition (ALD) to apply an ultra-black coating to an uneven surface. The upgraded coating is more resilient and effective than its predecessors. As such, the development could have major implications for multiple industries, including optics, space exploration, renewable energy, and much more. Here’s what you need to know.

The researchers have published their findings and explained in detail how they created a durable ultra-black thin-film coating designed specifically for aerospace-grade magnesium alloys. These alloys are commonly used in space exploration, where weight and durability are major concerns.

Those unfamiliar with the process used to create high-tech devices and optics may not understand the vital importance of finding non-reflective black material. Notably, stray light can cause disruptions in these devices and significantly reduce quality. Consequently, there has been a steady line of improvements in search of the blackest non-reflective material.

These coatings will help to advance aerospace technologies where new material combinations can create stronger materials. These lightweight materials are found on many satellites, spacecraft, and suits. They are also commonly used in the aeronautical sector due to their resilience and proven durability.

In Search of the Blackest Black

As precision optics continue to increase, the demand for more light-absorbing materials expands. Until recently, a thin black film was used to create a light absorbing non-reflective material inside camera lenses and other curved or oddly shaped devices. ALD coating provides a better solution that can be applied more easily and is resistant to extreme conditions. The process creates super thin and even coats that leave no areas untouched.

Problems with the Current Coating Materials and Methods

There are many reasons why existing ultra-black coating techniques are insufficient for today’s high-end optical and electronic devices. The most popular coating techniques currently rely on coatings that use fragile material, including vertically aligned carbon nanotubes or black silicon. These materials can’t withstand harsh environments without degrading quickly. They’re also expensive and hard to create.

Additionally, it’s difficult to apply these coatings to complicated structures. Since uneven application results in less durability and reduced performance, more researchers have dedicated efforts toward creating more absorbent alternatives. As lenses and other optical devices become more complex, it becomes critical to research and create better ways of evenly applying non-reflective light-absorbing material.

Enter Atomic Layer Deposition (ALD)

Atomic Layer Deposition (ALD) helps to solve many of the main issues faced by manufacturers and researchers regarding coatings. The process relies on vacuum-sealed rooms where gas is pumped in and leaves a thin layer on the surface. This method is called film growth and it provides manufacturers with an easy way to make complex materials using layers.

The ALD method produced impressive results with a test showing that 99.3% of light was absorbed by this ultra-black material. These improvements come from the more uniform film coverage and use of new light-absorbing materials. Specifically, researchers introduce a new method that uses two layers to improve durability.

The base layer uses Titanium–aluminum–carbon composite (TiAlC). This composition has ultra-light absorbing qualities and can hold up under heavy use in harsh environments including space. The second layer uses a dielectric material silicon nitride (SiO2)  which is ideal for preventing reflections. Together, these layers can absorb 99.3% of light across a span of wavelengths.

History of ALD

The idea of using ALD to apply thin coatings has been around for +60 years. Interestingly, two inventors claimed the discovery of the technology. These independent efforts went about the process differently but got the same results: an atomic thin layer of coating.

In the 1960s, Soviet researchers accomplished this task using a process called molecular layering. The discovery wasn’t immediately recognized in the West as the political climate was tentious following the end of WWII. However, many researchers realized early on that this technology would be pivotal in the next-gen devices.

A decade later, a Finnish research team led by Dr. Tuomo Suntola successfully used a new method called atomic layer epitaxy to provide thin even coats of light-absorbing material to devices. This method was an instant hit with manufacturers, leading to Finland becoming a hub for ALD development for decades.

From there, ALD science continued to expand with breakthroughs occurring in photovoltaics, catalysis, manufacturing of semiconductors, and beyond. Today, you live in a world surrounded by this technology. From your smartphone to your solar panels powering your home, ALD processes have improved the lives of billions.

Impressively, the latest processes have developed to the point that they can deposit uniform and conformal films on complex, 3d objects with atomic precision. ALD offers an ultra-thin coating that can go as low as one atom thick. Notably, the coating is so thin it can be considered 2D.

ALD Uses

Today, ALD manufacturing processes are a crucial component of the market. These thin layers provide a strong and effective way to protect items from unwanted energy sources. Here are some of the most exciting ways in which ALD could improve your life in the future.

Solar Cells

Researchers have made significant strides in photovoltaics thanks to the use of ALD technology to trial new materials and structures. Today’s solar panels are inefficient, with the best option only averaging +30% energy conversion. Much of this energy gets lost to heat and reflected off the surface of the cells into the atmosphere.

ALD solar panels could capture more light and prevent leaks. Additionally, they could be made to withstand the harshest environments, including those found on other planets where they would be required to run space exploration devices for years. As such, many believe that ALD solar cells will be what powers the next moon rover and other space ventures.

Lithium Batteries

Lithium-ion battery (LIB) technology provides high-energy density and low self-discharge batteries. These batteries rely on chemical reactions that occur between the electrolyte and the anode. Sadly, the current solid electrolyte interfaces (SEI) consume a percentage of the ions permanently making them wasteful.

Using ALD to coat electron layers could help to prevent losses in performance and reduce degradation over time. ALD processes can accomplish these tasks because they are both thin and can be applied evenly with no holes in the surface on an atomic level. This coating prevents unwanted cross-contamination on an atomic level.

MicroChips

Microchip technology continues to revolutionize the world by making more advanced electronics smaller and more reliable. The current microchip is light years ahead of its predecessor but still lacks in many aspects. Fr one, it is very energy intensive which means all of your smart devices add up to equal a lot of energy usage.

Recognizing the importance of energy sustainability, the U.S. Department of Energy (DOE) awarded DOE’s Argonne National Laboratory $4 million to fund their next-gen ALD chip research. The goal of the project is to find new materials that can reduce microchip energy requirements by up to 50x. If successful, the entire market could benefit.

Part of the approach seeks to solve the “von Neumann bottleneck” which is a term that refers to the massive amount of energy used by computers simply moving data between logic and memory chips. Argonne will use ALD to create low-energy alternatives to help combat excessive energy consumption before it’s too late.

Space

Space exploration is one of the sectors in which ALD has played a significant role over the last decade. Space research requires devices that can handle adverse environments unlike anything on Earth. A satellite might have to withstand temperatures of +500Fh on one side, while the other side of the device is freezing at below-zero temperatures.

These extreme temperatures and conditions can wreak havoc on optical devices and electronics. ALD provides the best solution to these issues. Additionally, researchers continue to expand its light-absorbing capabilities. Today’s space optic relies on material that can also absorb ultraviolet and infrared light to provide a light sterile environemnt.

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ALD Market Leaders

The ALD market continues to expand to meet the growing demand of electronic manufacturers and researchers. These ALD providers have secured strong strategic partnerships and have proven to provide reliable services. Here are just a few of the top ALD providers driving innovation today.

1. Argonne

Argonne is a popular research center that works with high-tech manufacturers, governments, and other researchers to create advanced coating options. The firm originated in the 1940s as an offshoot of the Manhattan Project. Back then, atomic energy was seen as the future.

Since that time, Argonne has become a multidisciplinary science and engineering research center but still focuses primarily on energy sustainability. The group leverages its downtown Chicago location to access a variety of industries and drive creativity in the energy physics and materials science markets.

2. Beneq

(Private)

In 1984, Beneq became the world’s first industrial production line to integrate ALD methods into its processes. This privately owned Finnish firm has been a pioneer in the market since ALD was created. Today, it provides high-end ALD equipment to firms and specializes in semiconductor manufacturing processes.

Beneq remains a pioneering force in the ALD sector and has been recognized as one of the most established names on this list. The group continues to offer new and innovative coating solutions. As such, many consider it a market leader.

3. CVD Equipment

CVD Equipment is another well-respected ALD provider. The group earned a reputation for providing precise and reliable chemical vapor deposition and thermal process equipment to the market. Today, CVD serves multiple industries, including the automotive and aerospace sectors.

CVD has been offering services for +40 years. this experience has enabled the firm to position itself as a pioneering force in the market. It has also enabled the company to enhance and optimize its processes to maximize performance.

4. Applied Materials

Applied Materials became a major player in the ALD market after acquiring Picosun in 2020. At that time, Picosun was one of the most active ALD providers in the industry. Applied Materials leveraged their experience and network to innovate new methods and strategies for applying ultra-thin layers..

Today, Applied Material offers ALD services to enterprise-level clients. These services include turnkey production lines and research offerings. Additionally, firms can leverage Applied Materials consulting to help streamline the creation and integration of ALD services.

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Artificial Intelligence Improves ALD

One of the reasons why ALD has improved over the last few years is the integration of AI algorithms. Specifically, machine learning algorithms enable developers to create and trial new compounds virtually. This capability significantly lowers R&D costs and enables developers to see how certain materials interact without needing special machines to accomplish the task.

Machine learning algorithms can run millions of trials to find potential weak points or thresholds. This style of AI is very effective and only requires to be taught once to complete tasks optimally. Additionally, learning neural networks could see AI recommending new materials and conducting testing and development on its own.

AI simulation is a game-changer for many reasons. For one,  these tests make it possible to test their creations to the absolute limit without damaging items in the real world. Developers can create, test, and readjust everything virtually before ever putting funding towards manufacturing methods. In this way, AI could be the key to unlocking new levels of resilience and application methods in the future.

ALD Market Expansion

The ALD market is on the rise, with reports showing that +4.46B in revenue was generated from the sale of ALD equipment in 2023. The same data highlights significant growth potential in the future, with 8.90% CAGR predicted over the next decade in the US market alone.

The report also shows the increased demand is the result of the continued miniaturization of electronic devices and improved manufacturing processes. Newer processes improve quality and reduce application costs. The same report also shows how increased demand for solar panels is another catalyst for ALD expansion.

It Can Always Get Blacker

The science of creating the blackest material will continue to evolve and drive innovation across the science sectors. From high-end optical devices to space exploration and capturing solar rays, ALD technologies are at the forefront of innovation. For these reasons, it’s smart to keep an eye on these firms in the coming months.

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