Not All Quantum Dots Are Created Equal

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I spent the last two weeks in Brussels, Belgium on a mission to help educate members of the European Parliament about quantum dots (QDs) and their potential impact on the display industry.  The goal of the trip was to provide facts and correct misunderstandings about quantum dots and their positive potential for business and society.  It seems our efforts were well received and appreciated by those with whom we met.

Brussels is beautiful.  It’s buzzing with energy, cultural and diplomatic diversity.  It’s very concentrated and most of what you might want to see and do is quite walkable.  Public transportation is easy, timely and very efficient.  The people are quite friendly and most speak English as a fallback to their home language.  They also share a sense of pride in being a part of an increasingly important political center. It’s truly one of the great cities of Europe – and I hope to return very soon.

In the past twelve months, quantum dot technology has captured the full attention of the display industry – by efficiently and inexpensively expanding the color gamut over most of today’s televisions and monitors by over 50 percent.   Industry adoption is accelerating, as is confusion about the technology.  So we at QD Vision are working to get some important facts on the table.

Because of the unique way they convert light, cadmium selenide and indium phosphide are the two most commonly used compounds in quantum dots for displays.  But this is where their similarity ends.  For instance:

Cadmium selenide dots deliver a wider color gamut.  Using industry-standard benchmarks, displays based on cadmium selenide dots show over 10% more colors than those based on indium phosphide.  And while this might be considered a “nice to have” by some for use cases such as entertainment and gaming, this performance gap becomes much more important when you consider the economic implications for e-commerce – and potentially life-saving implications for medical diagnostics.

Color matters… and it will only matter more in the years ahead.

Cadmium selenide-based edge optic solutions are more affordable.  Cadmium selenide dots are more stable in high heat and flux conditions.  This means they can be placed closer to the LEDs.  As a result, you need to use about one-20th the material of an indium phosphide-based solution.  And while the cost of the dots is relatively insignificant, the cost of the packaging is not.  In order to use indium phosphide dots, you have to embed them in an expensive film that covers the whole display screen – almost a full square meter for a typical 55” television.  As a result, indium phosphide-based solutions are up to three times more expensive to implement than edge-optic solutions using cadmium selenide.

Cadmium selenide-based QD displays are more energy-efficient.  In lab tests, changing only the quantum dot material, cadmium selenide-based QD displays consume a minimum of 20% less energy than indium phosphide-based QD displays.   In fact, lab tests show that cadmium selenide-based QD displays are significantly more energy efficient than any other wide color gamut technology available today – including RG Phosphor, OLED and indium phosphide QDs – while producing the benefit of a much wider color gamut.

This energy-efficiency advantage is of great importance to the European Parliament, because of it’s potential implications for all Europeans:

  • Cadmium selenide-based QD displays could save Europeans over 3 billion Euros/year in energy costs – and still deliver the widest color gamut commercially available today.
  • This translates directly to almost 7 million tons of avoided CO2 production per year in Europe alone.
  • And, because fossil fuel-burning electrical production plants are a leading source of free cadmium in the atmosphere, cadmium selenide-based QD displays result in a net reduction in free cadmium in the environment. That’s right, 1.5 mg of cadmium selenide in a typical 55” display leads to a net 40 mg reduction in free cadmium over the average life of a television.

Said another way, QD displays based on indium phosphide actually lead to more free cadmium in the environment than those using cadmium selenide.  It may seem counterintuitive, but it’s true.

So, to summarize:

  • Cadmium selenide quantum dot solutions deliver a wider color gamut.  Opening up new economic opportunities for businesses and better experiences for consumers worldwide.
  • Cadmium selenide quantum dot solutions are more affordable.  Why shouldn’t everyone have access to wide color and great energy savings?
  • Cadmium selenide quantum dot solutions are more energy-efficient.  Lower energy costs.  Less carbon dioxide.  Less free cadmium in the atmosphere.

There is currently no alternative quantum dot technology that can fill the shoes of cadmium selenide quantum dots.  Our goal is to have Parliament understand the full story – and continue to make this technology available until an equally-performing alternative becomes commercially available.


By John Volkmann, CMO, QD Vision

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