Out of this world germanium properties
Critical Minerals Alliances 2022 - September 12, 2022
Last updated 9/27/2022 at 2:06pm
Tech metalloid boasts superior semiconductor, optical qualities
From NASA's Gateway space station that will serve as a critical outpost circling the Moon to more down-to-Earth applications such as quantum computers that are millions of times faster than their classical counterparts and fiber optic cables that send data at the speed of light, germanium is among the techiest of the tech metals.
"The extensive use of germanium for military and commercial applications has made it a critical material in the United States and the rest of the world," the U.S. Geological Survey penned in a report on critical minerals.
Germanium traces its technological roots back to the 1950s, when scientists developed the transistor to replace vacuum tubes in the enormous mainframes of the day – a discovery that led to modern smartphones that are hundreds of thousands of times more powerful than the Apollo-era computers that guided Man's first flights to the Moon.
While germanium is the original and more powerful transistor semiconductor, it was supplanted by silicon, a more abundant and less expensive material that has become the namesake for the global capital of computer technology and the Digital Age.
Despite Germanium Valley never becoming a reality, the superior semiconducting and optical properties of this critical metalloid are empowering space exploration and high-speed communication networks here on Earth.
As an intrinsic semiconductor, germanium is a powerful ingredient in triple-layered solar panels that are much more efficient at converting light into electricity than typical photovoltaic cells.
"Germanium substrates are used to form the base layer in multijunction solar cells, which are the highest efficiency solar cells currently available," according to the USGS.
These highly efficient but more expensive germanium-infused solar cells are the preferred photovoltaic power source for space missions.
"Whereas silicon is optimised to convert one specific part of the light spectrum into electricity, germanium allows for triple-junction cells. Each junction converts a different portion of the light spectrum into electricity, so overall conversion efficiency is a lot higher," explains Bendix De Meulemeester, business development director at Umicore Electro-Optic Materials, which provides germanium solar panels for past, current, and future space applications.
This germanium solar cell technology will power the Lunar Orbital Platform-Gateway, more commonly known as Gateway, which will soon serve as an outpost for long-term missions to Mars and beyond.
In the meantime, germanium solar cells are powering the Curiosity rover exploring Mars in preparation for human arrival.
"The solar cells are stacked in three layers on the rover's solar arrays and, because they absorb more sunlight, can supply more power to the rover's re-chargeable lithium batteries," NASA Jet Propulsion Laboratory explains.
Superior optical qualities
Despite its superlative-earning semiconductor notoriety, germanium's superior optical qualities – transparent to the infrared electromagnetic spectrum, can be formed into glass, exceptionally high refractive index, and low chromatic dispersion – are what drive the highest demand for this metalloid.
"The major use of germanium worldwide is for fiber-optic systems, whereby germanium is added to the pure silica glass core of fiber-optic cables to increase their refractive index, minimizing signal loss over long distances," USGS inked in a germanium fact sheet.
M2 Optics CEO Kevin Miller says chromatic dispersion, or the flattening of the initially sharply defined binary pulses of information, is an equally serious consideration when it comes to sending data over long distances via fiber optics.
"This degradation makes the signals (ones and zeros) more difficult to distinguish from each other at the far end of the fiber," he explains.
The International Energy Agency estimates that 5 billion people will be using the internet by 2025, a roughly 40% increase over the 3.6 million in 2018. This increase of people streaming movies, games, and other large data files at lightning-fast speeds continues to drive the demand for more fiber-optic cable and the germanium that goes in it.
As a result, the global fiber optic components market is expected to expand at a compound annual growth rate (CAGR) of 8.1%, reaching $36.3 billion by 2027.
Infrared imaging devices used by the military, law-enforcement agencies, and increasingly in the private sector are another major driver of demand for the optical qualities offered by germanium.
"Infrared optical devices improve a soldier's ability to operate weapon systems in harsh conditions effectively, and they are increasingly used in remotely operated unmanned weapons and aircraft," the USGS inked in its germanium report. "Infrared optical devices are also used for border patrol and by emergency response teams for conducting search-and-rescue operations."
While military and law enforcement are the major buyers of night-vision technology, USGS said commercial applications for thermal imaging devices that use germanium lenses have increased during the past few years.
Blockchain traces byproduct
Like many of the minerals and metals deemed critical to the U.S., germanium is not mined as a primary commodity. Instead, the metalloid is recovered as byproduct from concentrates from mining zinc and other base metals.
"As a byproduct metal, the supply of germanium is heavily reliant on zinc production," the USGS penned in its report.
Teck Resources Ltd.'s Red Dog Mine in Alaska, the second-largest producer of zinc on Earth, is also a globally significant source of germanium.
In the U.S., germanium was also recovered as byproduct of zinc mining and refining in Tennessee, as well as recycled from industry-generated scrap at a refinery in Oklahoma.
"Based on an analysis of zinc concentrates, U.S. reserves of zinc may contain as much as 2,500 tons of germanium," USGS inked in its 2022 Mineral Commodity Summaries.
As operator of both Red Dog and Trail Operations – a refinery in southern British Columbia that processes the concentrates from Red Dog and other zinc mines – Teck is the largest germanium producer in North America.
The high-quality germanium products produced at Trail are used in fiber optic cables, high-speed computer chips, quantum computer transistors, solar cells, light-emitting diodes (LEDs), and night vision goggles, to name a few.
With the refinery processing concentrates from other mines, it is hard to track exactly how much of this germanium comes from Red Dog concentrates.
This situation has created a conundrum for agencies tracking critical minerals.
"Because zinc concentrates are shipped globally and blended at smelters ... the recoverable germanium in zinc reserves cannot be determined," USGS penned in its mineral commodities report.
With the use of blockchain technology, it will soon be possible to track Red Dog germanium from mine to customer.
Working with DTL Labs, a leading provider of blockchain-enabled technology, Teck is piloting a project that traces germanium from Red Dog through the Trail refinery and to a fiber optic cable manufacturer.
Over the past decade, businesses have identified many uses for blockchain technology, from the settlement of financial records to smart contracts and reliable, transparent traceability of supply chains.
DLT Lab's DL Asset Track technology will embed data into a digital passport that includes information on environmental, social and governance (ESG) along the entire germanium supply chain.
"DLT is proud that its DL Asset Track product is being adopted by Teck in setting the standard for an innovative product passport," said DLT Labs CEO Loudon Owen. "This product passport collects, stores, and provides reliable, tamper-proof, and real-time data at every stage in the resource supply chain from end-to-end, including comprehensive information about the provenance of the resources. Certainty of mine of origin, provenance and single source of truth are essential building blocks for an effective ESG program."
Teck believes that traceability and assurance of both origin and handling along the supply chain can play a role in supporting responsible production more broadly for essential metals and minerals.
"Teck is proud to be advancing the first use of blockchain technology to trace the critical mineral germanium from the mine all the way to the customer," said Teck Resources Senior Vice President of Sustainability and External Affairs Marcia Smith. "Ensuring the environmental and social responsibility throughout the metals production chain provides our customers and downstream consumers with the confidence that their products are sourced responsibly."