"Vantablack" absorbs an astonishing 99.965% of visible light, allowing only the smallest fraction of light to escape, pushing the boundaries of the darkest material ever created by humans. When standing in front of it, shapes, contours, and details nearly disappear, creating the sensation of gazing into an endless, unfathomable black void—as if you're staring directly into a black hole.

Pure black objects are indeed a rarity in nature. While blue skies and green lakes are common sights, truly black flowers or oceans are hardly ever encountered. In fact, pure black might not exist at all in our daily surroundings or in the natural world. Take carbon black ink, for instance—it may look black, but when diluted in water, it reveals a purple hue. On closer inspection, what we perceive as black is often a blend of various colors, illustrating that our perception of black objects is more complex than it initially seems.

So why is black so rare? In reality, objects don't possess color on their own. The colors we perceive result from how an object’s surface reflects or absorbs light and how our eyes and brain interpret this information. When light hits an object, specific wavelengths are reflected into our eyes, creating the perception of color. The light that humans can see, known as visible light, spans wavelengths from approximately 380 to 750 nanometers. Different wavelengths are processed by the brain to be seen as distinct colors. In fact, the human eye can detect around 10 million different colors, yet true black remains elusive, as it represents the near-complete absorption of visible light, with minimal to no reflection for the brain to interpret.

An object appears black for two main reasons: one is a lack of light from the source (which we won’t go into detail about here), and the other is when the object absorbs almost all visible light, preventing any light from being reflected back to our eyes. This is why we perceive the object as black. In reality, materials that can absorb all visible light are extremely rare, which is why truly black substances are so scarce.

How difficult is it to achieve EC black technology? Currently, no material exists that can absorb the entire visible light spectrum. Developing the right black materials is crucial and represents the main bottleneck in the field of EC technology research. There are three key points to consider:

First Point: The Material's Ability to Absorb the Full Visible Light Spectrum

Every material has its own optical, chemical, and physical properties. For black materials, they need to absorb almost all wavelengths of visible light, from 380 to 750 nm. Most materials find it difficult to maintain uniform and efficient absorption across such a wide spectrum. Achieving this requires the synthesis of new materials and ensuring that hundreds or even thousands of different materials are compatible with each other. This process necessitates a large amount of experimentation and validation.

Second Point: Maintaining Dynamic Uniformity and Consistency

As black materials transition from transparent to tinted states, complex reactions occur within the material during this continuous dynamic color change process. Even if the right material combination is found, ensuring uniform color throughout the dimming process remains a significant challenge. It’s similar to jade glass: its transparency allows you to see internal patterns or impurities, and achieving color uniformity means that after cutting the jade into many pieces, each small segment and face must remain pure without any pigment deposits or impurities. Additionally, when combining different functional materials, such as conductive and electrochromic materials, their dispersion and compatibility vary, and ensuring their even distribution is crucial for consistent overall color. Furthermore, during the production of black materials, precise process control is essential. Functional films formed through coating or deposition methods must have extremely uniform thicknesses. Even slight variations can result in inconsistent optical performance, affecting color uniformity. Controlling and measuring the thickness of these ultra-thin films presents a significant challenge.
 

Third Point: Long-Term Material Stability

This has a direct impact on whether new materials can satisfy practical application demands, as well as their durability and overall performance. From a technical perspective, achieving such outcomes is highly challenging. To absorb light across the full visible spectrum, special or composite materials are typically needed. However, these materials add complexity to the development process and can compromise long-term chemical and physical stability, especially since prolonged light exposure may degrade performance characteristics. Additionally, synthesizing high-performance materials requires intricate processes, including precise control of reaction conditions and rigorous testing to ensure they meet stringent performance standards.

EC black materials are often regarded as the "crown jewel" of the industry. Ambilight is currently the only technology company capable of mass-producing black smart films. The black smart sunroof has already been applied in several mainstream vehicle models, marking a significant milestone in the development of EC technology. This achievement demonstrates humanity's ultimate pursuit of mastery over light and color.