Light-emitting diodes (LEDs) were invented in 1994 as high-brightness, highly efficient light bulbs. LEDs work like solar panels but in reverse, converting electrons to photons rather than the other way around. They use 90% less energy than incandescent bulbs, and half as much as compact fluorescents, for the same amount of light. While other lighting technologies convert energy into heat (and most of it wasted), LEDs convert 80% of their energy use into creating light.
There are many environmental benefits to LEDs. Their efficiency in converting energy into light, rather than heat, helps reduce electricity consumption and air-conditioning loads. For people without access to ample energy, LEDs can be illuminated with small solar cells and can replace expensive kerosene lamps and their noxious fumes and emissions. When LEDs are used in streetlights, they can save up to 70% of energy and significantly reduce maintenance costs.
Project Drawdown predicts that if LED lighting becomes ubiquitous in both the residential and commercial lighting market, it can help avoid between 10.2 - 10.8 gigatons of CO2 emissions in residences, and between 5.9 - 6.7 gigatons in commercial buildings. But to get there, the global market share of LEDs needs to scale rapidly:
- In 2018, LED lights accounted for 3% of the total commercial lighting and 2% of the residential lighting market
- By 2050, LEDs should account for 95% and 90% of the residential and commercial markets, respectively
- That’s 12.82% CAGR for residential LED, and 11.21% CAGR for commercial LED lighting between 2018 and 2050.
AXT, Inc. (stock ticker: AXTI) designs, develops, manufactures and distributes compound and single element semiconductor wafer substrates. Their wafer substrates are used in 5G infrastructure, data center connectivity, passive optical networks, LED lighting, lasers, sensors, power amplifiers, etc. Headquartered in Fremont, California, AXT, Inc. has manufacturing plants in China.
AXTI's Role in Drawdown
AXT, Inc. manufactures a wide variety of substrate wafers, but their semi-conducting gallium arsenide (GaAs) substrates (p. 3) are what’s used to create high brightness LEDs. LEDs incorporating semi-conducting GaAs substrates are often used to backlight wireless devices and liquid crystal display (LCD) TVs, automotive panels, signage, display and lighting applications. A new application is 3-D sensing chips using vertical cavity surface emitting lasers as an array of lasers on a single chip that can be used in cell phones and other devices. GaAs wafers can also be used for making micro-LEDs.
AXTI: What We Like
We’ll update this section once AXT makes sustainability information available.