New applications compete with solar for Te supply

UK-based cadmium zinc telluride (CZT) producer Kromek has signed multiple deals in the past month to develop CZT detectors for medical imaging, which is among the applications increasingly competing with solar for tellurium supply.

Kromek is one of only four companies globally that manufacture CZT, which it uses to produce imaging and detection equipment for civil nuclear applications, medical imaging and security screening.

Kromek has agreed to collaborate with sensor technology supplier Analogic on the development of next-generation CZT-based detectors for photon-counting computed tomography (PCCT) equipment in the medical imaging and security sectors.

PCCT detectors using CZT address limitations in conventional computed tomography (CT) detectors to increase spatial and energy resolution and reduce radiation doses, according to Kromek. This can improve image quality to enable the early detection of illnesses in medical imaging and identify dangerous items in security scans.

Kromek will integrate CZT sensors into Analogic's detector designs to optimise its detection systems. It will also provide the production capacity to support Analogic's PCCT demand.

Kromek has also signed an initial seven-year agreement this week with an unnamed tier 1 original equipment manufacturer (OEM) in the health technology sector to develop CZT-based detectors for use in advanced medical imaging scanners.

The agreement will transition to a longer commercial supply phase after a short development period, the companies said. The collaboration across development and supply will aim to facilitate the customer's progress in next-generation imaging-based technologies for precision diagnosis and therapy.

In March, Kromek signed repeat orders valued at a total of $1.1mn from three medical imaging customers in its key target market of single-photon emission computed tomography (SPECT).

Commercial demand for Kromek's CZT products for CT and SPECT applications has been increasing in the second half of its 2023 financial year ending in June, in addition to its long-term contracts, the company said.

The deals include a $300,000 order for detectors for niche SPECT applications, which is expected to be delivered in the company's 2023 financial year. A $563,000 order from an OEM for niche SPECT applications and a $205,000 order for niche medical imaging applications are from long-term customers, with delivery due to start before June and conclude in the first half of the 2024 financial year.

Kromek reported a 50pc year-on-year increase in revenue during its fiscal third quarter ending in March. The company expects strong revenue growth for the full financial year as it continues to trade in line with market expectations.

Tellurium market could tighten on new demand sources

Applications such as medical imaging and security scanning are increasingly using advanced semiconductor materials including CZT and gallium nitride, competing with their primary applications for supply.

The largest share of the world's tellurium output is used to produce cadmium-telluride (CdTe) solar panels — about 40pc — and the rapidly growing deployment of renewable energy capacity is increasing the industry's consumption. US-based First Solar, one of the world's largest CdTe panel manufacturers, has ambitious plans to ramp up its production capacity that would drive its tellurium consumption beyond the current level of global supply.

At the same time, demand from thermoelectric device manufacturers, which account for about 30pc of the market, and metallurgical applications, which account for about 15pc, is expected to rise in the coming years.

Bismuth telluride is used in thermoelectric devices for cooling and energy generation as well as sensors, and companies such as First Tellurium are developing new applications for tellurium in the sector. First Tellurium is also among the companies working to develop lithium tellurium batteries for electric vehicles.

Rising demand for nanostructured tellurium semiconductors and the rapid adoption of artificial intelligence are expected to add another new source of consumption.

As tellurium is largely produced as a by-product of copper mining, supply depends on demand for copper refining. China accounted for an estimated 53pc of global output of approximately 640t in 2022, with Russia, the second-largest producer, accounting for 12.5pc. Ongoing geopolitical tensions are giving further impetus to efforts to identify alternative sources of supply to meet the demand growth.

By Nicole Willing