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The last time I spent much time thinking about LED bulbs was some seven years ago, when a kitchen remodel turned out more operating room than cozy family gathering place. What went wrong? The architect determined that the contractor had purchased the wrong temperature of LEDs; a problem easily fixed.

Since then, I occasionally noticed some advances in LED light bulbs at CES and gadget shows—like dimmable LEDs (now common) and smart bulbs that connect to home Wi-Fi networks for remote control. But nothing that made LEDs shine.

So the last thing I expected when checking out the more than 40 new products at Pepcom’s holiday launch event was to get excited about a couple of LED bulbs. One of these gadgets acts as a Bluetooth speaker that automatically networks with nearby speaker-bulbs to create a surround-sound effect, the other has an adjustable color temperature and a unique user interface. My third gadget pick, a water-powered shower speaker, doesn’t light up, but is about as unobtrusive as a household light bulb.

Here are the details. (Note that this was a virtual event, so the demos and discussions, while held live, were remote; I haven’t actually held any of these gadgets in my hands, much less tested them in the real world.)

1. GE’s LED+ Speaker bulbs

The Bluetooth speaker in one of these LED+ bulbs can work alone, or as part of a surround-sound network of as many as 10 bulbs. Company representatives indicated that the gadgets come in a variety of standard bulb sizes to fit lamps, floodlights, or recessed lighting, starting at about US$30. Each bulb comes with a remote control, though in a multi-speaker network only one bulb needs to be paired with the remote; it then acts as a parent and controls the other bulbs in its vicinity.

2. Feit Electric’s Selectable Color bulbs

These LED bulbs vary color temperature from about 2700K to 6500K, depending on the particular version. As I learned with my kitchen remodel mistake, color temperature matters a lot; it can make the difference between a space feeling like an office or operating room instead of a cozy den. I was particularly impressed by the simple interface that doesn’t require an app or a remote—flicking the light switch on and off cycles through the color options; circuitry in the bulb recognizes the short sequence of power interruptions. And Feit’s representatives made the pitch that in today’s stay-at-home Covid times, the ability to change the feel of a room matters even more than usual, not a bad selling point. Prices, again, vary by type of bulb, but generally start at about US $10, a premium of a couple of dollars over a standard LED bulb.

Another clever placement of a Bluetooth speaker in an ordinary household object, the cool factor of Ampere’s shower speaker isn’t that it’s waterproof, it’s that screws into the shower head to run on hydropower from the shower flow. I was already slightly familiar with the potential of shower power—I have an outside shower that’s lit by LEDs built into the shower head and powered by the water flow. Unlike that gadget, however, Ampere’s device includes a battery that can store power for listening while the shower is off. Company representatives indicated that the gadget produces about 120 milliampere per hour with standard water flow, slightly less or more depending on water pressure, and will retail for around $70. (It is currently taking preorders via Kickstarter .)

Tekla S. Perry is a senior editor at IEEE Spectrum. Based in Palo Alto, Calif., she's been covering the people, companies, and technology that make Silicon Valley a special place for more than 40 years. An IEEE member, she holds a bachelor's degree in journalism from Michigan State University.

Formerly rival technologies have come together in Samsung displays

Sony's A95K televisions incorporate Samsung's new QD-OLED display technology.

All these products use display panels manufactured by Samsung but have their own unique display assembly, operating system, and electronics.

I took apart a 55-inch Samsung S95B to learn just how these new displays are put together (destroying it in the process). I found an extremely thin OLED backplane that generates blue light with an equally thin QD color-converting structure that completes the optical stack. I used a UV light source, a microscope, and a spectrometer to learn a lot about how these displays work.

Samsung used a unique pixel pattern in its new QD-OLED displays.

As for the name of this technology, Samsung has used the branding OLED, QD Display, and QD-OLED, while Sony is just using OLED. Alienware uses QD-OLED to describe the new tech (as do most in the display industry).

For more than a decade now, OLED (organic light-emitting diode) displays have set the bar for screen quality, albeit at a price. That’s because they produce deep blacks, offer wide viewing angles, and have a broad color range. Meanwhile, QD (quantum dot) technologies have done a lot to improve the color purity and brightness of the more wallet-friendly LCD TVs.

In 2022, these two rival technologies will merge. The name of the resulting hybrid is still evolving, but QD-OLED seems to make sense, so I’ll use it here, although Samsung has begun to call its version of the technology QD Display.

To understand why this combination is so appealing, you have to know the basic principles behind each of these approaches to displaying a moving image.

In an LCD TV, the LED backlight, or at least a big section of it, is on all at once. The picture is created by filtering this light at the many individual pixels. Unfortunately, that filtering process isn’t perfect, and in areas that should appear black some light gets through.

In OLED displays, the red, green, and blue diodes that comprise each pixel emit light and are turned on only when they are needed. So black pixels appear truly black, while bright pixels can be run at full power, allowing unsurpassed levels of contrast.

But there’s a drawback. The colored diodes in an OLED TV degrade over time, causing what’s called “burn-in.” And with these changes happening at different rates for the red, green, and blue diodes, the degradation affects the overall ability of a display to reproduce colors accurately as it ages and also causes “ghost” images to appear where static content is frequently displayed.

Adding QDs into the mix shifts this equation. Quantum dots—nanoparticles of semiconductor material—absorb photons and then use that energy to emit light of a different wavelength. In a QD-OLED display, all the diodes emit blue light. To get red and green, the appropriate diodes are covered with red or green QDs. The result is a paper-thin display with a broad range of colors that remain accurate over time. These screens also have excellent black levels, wide viewing angles, and improved power efficiency over both OLED and LCD displays.

Samsung is the driving force behind the technology, having sunk billions into retrofitting an LCD fab in Tangjeong, South Korea, for making QD-OLED displays While other companies have published articles and demonstrated similar approaches, only

Samsung has committed to manufacturing these displays, which makes sense because it holds all of the required technology in house. Having both the OLED fab and QD expertise under one roof gives Samsung a big leg up on other QD-display manufacturers.,

Samsung first announced QD-OLED plans in 2019, then pushed out the release date a few times. It now seems likely that we will see public demos in early 2022 followed by commercial products later in the year, once the company has geared up for high-volume production. At this point, Samsung can produce a maximum of 30,000 QD-OLED panels a month; these will be used in its own products. In the grand scheme of things, that’s not that much.

Unfortunately, as with any new display technology, there are challenges associated with development and commercialization.

For one, patterning the quantum-dot layers and protecting them is complicated. Unlike QD-enabled LCD displays (commonly referred to as QLED) where red and green QDs are dispersed uniformly in a polymer film, QD-OLED requires the QD layers to be patterned and aligned with the OLEDs behind them. And that’s tricky to do. Samsung is expected to employ inkjet printing, an approach that reduces the waste of QD material.

Another issue is the leakage of blue light through the red and green QD layers. Leakage of only a few percent would have a significant effect on the viewing experience, resulting in washed-out colors. If the red and green QD layers don’t do a good job absorbing all of the blue light impinging on them, an additional blue-blocking layer would be required on top, adding to the cost and complexity.

Another challenge is that blue OLEDs degrade faster than red or green ones do. With all three colors relying on blue OLEDs in a QD-OLED design, this degradation isn’t expected to cause as severe color shifts as with traditional OLED displays, but it does decrease brightness over the life of the display.

Today, OLED TVs are typically the most expensive option on retail shelves. And while the process for making QD-OLED simplifies the OLED layer somewhat (because you need only blue diodes), it does not make the display any less expensive. In fact, due to the large number of quantum dots used, the patterning steps, and the special filtering required, QD-OLED displays are likely to be more expensive than traditional OLED ones—and way more expensive than LCD TVs with quantum-dot color purification. Early adopters may pay about US $5,000 for the first QD-OLED displays when they begin selling later this year. Those buyers will no doubt complain about the prices—while enjoying a viewing experience far better than anything they’ve had before.