Stanford researchers have improved the brightness and efficiency of affordable perovskite LEDs. However, a setback arose as these lights exhibited rapid burnout within minutes of use. Addressing limitations in PeLEDs’ atomic structure is crucial, despite their simple manufacturing process. Thus, Congreve Lab plans to tackles PeLED’s challenges with generating violet and ultraviolet light.

Stanford researchers have made significant advancements in brightness and efficiency by manipulating the composition of perovskite LEDs, a more affordable and readily produced type of LED. However, they encountered a setback as the lights would cease to function after only a few minutes of use.

Researchers tested a method to improve the brightness and efficiency of perovskite LEDs, or PeLEDs. They are a cheaper and easier-to-make alternative Researchers tested a method to improve the brightness and efficiency of perovskite LEDs, or PeLEDs. They are a cheaper and easier-to-make alternative, but this revolutionary molecular additive improves LEDs but reduces lifespan. These results serve as a powerful reminder of the necessary trade-offs that must be thoroughly comprehended in order to propel this particular class of materials forward.

Electrical engineering assistant professor and senior author on paper, Dan Congreve said, “We took some big steps towards understanding why it’s degrading. The question is, can we find a way to mitigate that while keeping the efficiency? If we can do that, I think we can really start to work towards a viable commercial solution.”

Perovskite LEDs are Unique

LEDs transform electrical energy into light by passing an electric current through a semiconductor material that emits light when an electric field is applied. However, the process of manufacturing semiconductors is both intricate and expensive, especially when compared to less energy-efficient lighting options such as incandescent and fluorescent lights.

Sebastian Fernסndez, lead author and PhD student in Congreve’s Lab said, “A lot of these materials are grown on expensive surfaces such as a four-inch sapphire substrate. Just to purchase this substrate costs a few hundred dollars.”

PeLEDs utilize a cutting-edge semiconductor called metal halide perovskites, which consists of a harmonious mixture of various elements. By growing perovskite crystals on glass substrates, engineers are able to achieve substantial cost savings in comparison to traditional LEDs. Perovskites can be dissolved in solution and applied onto glass to create a light-emitting layer. This is a simpler production process compared to regular LEDs.

Perovskite LEDs: Exploring the Possibilities and Constraints.

PeLEDs are advantageous in the following ways:

  • Increase the viability of energy-efficient indoor lighting throughout a greater portion of the built environment, thus diminishing energy consumption.
  • PeLEDs possess the potential to enhance the color purity of smartphone and TV displays.

In the words of Prof. Congreve, “A green is more green, a blue is more blue. You can literally see more colors from the device.”

Currently, many PeLEDs lose their brightness quickly and are not as energy-efficient as standard LEDs. This is because of defects in the atomic structure of the perovskite material.

Prof. Congreve explains, “There should be an atom here, but there’s not. Energy goes in there, but you don’t get light out, so it harms the overall efficiency of the device.”

Brightness vs. Longevity

Revolutionary molecular additive improves LEDs but reduces lifespan
Picture Credits: Congreve Lab Stanford.

To address these challenges, Fernסndez expanded on a method pioneered by Congreve and Mahesh Gangishetty, an accomplished chemistry assistant professor at Mississippi State University who is also a co-author of the research article. A considerable number of energy-inefficient voids are found in perovskites specifically in the areas where lead atoms should be located.

Efficient PeLEDs with reduced performance time could be improved by replacing 30% of the lead in perovskite with manganese atoms, the team significantly improved their brightness, increased the efficiency by almost three times, and extended the lifespan from less than a minute to 37 minutes.

Sebastian Fernסndez said, “Lead is extremely important for light emission within this material, but at the same time, lead is known to be toxic. This type of lead is also water-soluble – meaning it could leak through, say, a cracked smartphone screen. People are skeptical of commercial technology that is toxic, so that also pushed me to consider other materials.”

Also See: 10 Benefits of LED Lighting on the Environment

Advancements and Obstacles on the Horizon

Revolutionary molecular additive improves LEDs but reduces lifespan which is why Fernסndez took it to the next level by blending a phosphine oxide known as TFPPO with the perovskite material. He further added, “I added it and saw the efficiencies just shoot up.”

The addition of the additive resulted in a remarkable enhancement, making the lights up to five times more energy-efficient than those solely with manganese boost. Furthermore, it unveiled one of the most vibrant glows ever observed in any PeLED.

However, there was a drawback to these gains, the lights dimmed to only half of their maximum brightness within a remarkably short span of two and a half minutes. However, the perovskites that were not treated with TFPPO managed to maintain their brightness for an impressive duration of 37 minutes.

Understanding the trade-off

Fernסndez plans to try out various phosphine oxide additives to observe their different effects and understand the reasons behind them.

Fernסndez says, “Clearly, this additive is incredible in terms of efficiency. However, its effects on stability need to be suppressed to have any hope to commercialize this material.”

Congreve Lab is dedicated to tackling additional challenges of PeLEDs, including their incapability of generating violet and ultraviolet light.

Source Considering both efficiency and stability in perovskite-based lighting


Elliot is a passionate environmentalist and blogger who has dedicated his life to spreading awareness about conservation, green energy, and renewable energy. With a background in environmental science, he has a deep understanding of the issues facing our planet and is committed to educating others on how they can make a difference.

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