What was the growth rate of the germanium substrate business in 2020
tory for expected future demand. In Q4 of 2020, however, our revenue achievement was spread across many customers and money applications.
We believe the current revenue diversity demonstrates the broad and sustainable nature of our growth opportunities in indium phosphide. It was in April of 2019 that we first mentioned 5G revenue on our earnings report. Let's say, a year later, 5G and its closely related power applications are driving significant growth in our indium phosphide revenue. Demand had been particularly strong in China and Taiwan, and we don't see any slowing in 2021, as 5G continues to roll out worldwide.
We believe capacity in our industry remains very tight. We have and will continue to run capacity at our Beijing facility to keep pace with customer demand. Scaling quickly and cost it effectively is something AXT is uniquely able to do, and we expect to gain market share because we have the shortest lead time among our primary competitors. In data center connectivity, the ever-expanding number of users, devices, and applications is driving the transition to technology that transports faster, more scalable infrastructures.
High-capacity connectivity will continue to be essential. In fact, many believe that the evolution from 100G to 400G will happen faster than the move to 100G. We are seeing this growth in silicon photonics reflected in our steady, strong demand in data center-related revenue. Moreover, we are pleased with the highly productive customer relationships we are developing in this area of our business, and we are applying the tier one processes we have developed to benefit customer experiences across our portfolio.
In 2021, we expect to see the meaningful emergence of additional new applications for indium phosphide in such areas as healthcare monitoring and consumer devices. Money are being innovatively driven by tier one players and showcase the unique properties of indium phosphide. These applications have the potential to represent an entirely new growth area, for which we are well-positioned and engaged. Now turning to gallium arsenide.
LED revenue continued to rebound, driven by high-end applications, including automotive. Wireless gallium arsenide revenue was down seasonally in Q4, but IoT applications seem to be providing a lift in ongoing demand for semi-insulating gallium arsenide substrates. New applications, both emerging today and on the horizon, include world-facing cameras, augmented and virtual reality, automotive sensors and biosensors and more. As we talked about previously, micro-LED may follow as the next major volume driver of gallium arsenide chips.
Micro LEDs are expected to consume less power, provide sharper contrast, and produce brilliant lighting and colors. Their applications are set to scale from wearable devices and handheld devices to very large screen, like high-end televisions of the future. While current market expectations vary greatly, and they are subject to change over time, we're seeing reports that the micro-LED market for small consumer devices like wearables and phones may eventually reach an annual demand of 2 million six-inch gallium arsenide substrates for the ready LED portion alone. If that comes to pass, it will be larger than the entire current market for semiconductor gallium arsenide substrate.
Regardless of the specific numbers, this is an exciting space that could add significant new values to the LED market in 2024 and beyond. Tier one players are already driving the development, and we believe that our wafers are being used for early stage activities. In recent quarters, with so much happening in other parts of our product portfolio, we haven't focused much of our business commentary on germanium substrate. But for the context, this area of our business grew more than 20% in 2020, after a significant slowdown in 2019.
The primary driver is the satellite solar cell market, which appears to have entered a period of recovery. We expect to see further improvement in 2021. Now turning to raw materials. This is an interesting, exciting time for o
tory for expected future demand. In Q4 of 2020, however, our revenue achievement was spread across many customers and money applications.
We believe the current revenue diversity demonstrates the broad and sustainable nature of our growth opportunities in indium phosphide. It was in April of 2019 that we first mentioned 5G revenue on our earnings report. Let's say, a year later, 5G and its closely related power applications are driving significant growth in our indium phosphide revenue. Demand had been particularly strong in China and Taiwan, and we don't see any slowing in 2021, as 5G continues to roll out worldwide.
We believe capacity in our industry remains very tight. We have and will continue to run capacity at our Beijing facility to keep pace with customer demand. Scaling quickly and cost it effectively is something AXT is uniquely able to do, and we expect to gain market share because we have the shortest lead time among our primary competitors. In data center connectivity, the ever-expanding number of users, devices, and applications is driving the transition to technology that transports faster, more scalable infrastructures.
High-capacity connectivity will continue to be essential. In fact, many believe that the evolution from 100G to 400G will happen faster than the move to 100G. We are seeing this growth in silicon photonics reflected in our steady, strong demand in data center-related revenue. Moreover, we are pleased with the highly productive customer relationships we are developing in this area of our business, and we are applying the tier one processes we have developed to benefit customer experiences across our portfolio.
In 2021, we expect to see the meaningful emergence of additional new applications for indium phosphide in such areas as healthcare monitoring and consumer devices. Money are being innovatively driven by tier one players and showcase the unique properties of indium phosphide. These applications have the potential to represent an entirely new growth area, for which we are well-positioned and engaged. Now turning to gallium arsenide.
 LED revenue continued to rebound, driven by high-end applications, including automotive. Wireless gallium arsenide revenue was down seasonally in Q4, but IoT applications seem to be providing a lift in ongoing demand for semi-insulating gallium arsenide substrates. New applications, both emerging today and on the horizon, include world-facing cameras, augmented and virtual reality, automotive sensors and biosensors and more. As we talked about previously, micro-LED may follow as the next major volume driver of gallium arsenide chips.
Micro LEDs are expected to consume less power, provide sharper contrast, and produce brilliant lighting and colors. Their applications are set to scale from wearable devices and handheld devices to very large screen, like high-end televisions of the future. While current market expectations vary greatly, and they are subject to change over time, we're seeing reports that the micro-LED market for small consumer devices like wearables and phones may eventually reach an annual demand of 2 million six-inch gallium arsenide substrates for the ready LED portion alone. If that comes to pass, it will be larger than the entire current market for semiconductor gallium arsenide substrate.
Regardless of the specific numbers, this is an exciting space that could add significant new values to the LED market in 2024 and beyond. Tier one players are already driving the development, and we believe that our wafers are being used for early stage activities. In recent quarters, with so much happening in other parts of our product portfolio, we haven't focused much of our business commentary on germanium substrate. But for the context, this area of our business grew more than 20% in 2020, after a significant slowdown in 2019.
The primary driver is the satellite solar cell market, which appears to have entered a period of recovery. We expect to see further improvement in 2021. Now turning to raw materials. This is an interesting, exciting time for o