The future of semiconductor technology, already fast-approaching miniaturization limits, lies in the advancement of semiconductor materials. This is important for power electronics, which are themselves advancing at blistering speeds with the proliferation of the electric vehicle (EV) and renewable energy industries. From sustaining higher voltages to expanding the limits of technology in general, the material science behind semiconductor advancements is a fascinating case study of how an already legendary technology continues to present, it would seem, limitless opportunities.
Wide Bandgap Semiconductors
Wide bandgap (WBG) semiconductors are considered the next generation (specifically, the third generation) of semiconductor technology. WBGs are made of unique materials that require a wider distance between electrons’ valence and conduction bands, passing electrical currents upwards of 1200–1700V. As a result, it makes much more efficient power electronics systems possible. Power converter switches, transistors, power diodes, and other power electronics components have all advanced light years ahead.
WBG semiconductors are often made of silicon carbide (SiC), which has high voltage-blocking properties and even functions better at higher voltages. Gallium nitride (GaN) is also common, providing higher operating frequencies while minimizing losses without using silicon at all. Diamond semiconductor materials show even greater promise — although, in practice, they’re much harder to apply (forgive the pun).
As we’ll explore below, more advanced semiconductor materials are improving countless other technologies. They’re facilitating benefits such as:
- Greater power electronics efficiency
- An ability to harness higher voltages
- Further reductions in size limits
- Higher thermal regulation
- Simpler designs
- Faster charging
Power Modules
Power modules help power electronic systems convert energy into electricity. Next-gen semiconductors continually lead to greater power module performance. Electric vehicle powertrains, for example, require SiC-based power modules to achieve lower conduction and switching losses.
SiC semiconductors also push the envelope on circuit performance and thermal management beyond what was possible with other materials. For example, SiC MOSFETs provide higher blocking voltages and lower on-state resistance than traditional silicon MOSFETs, which are less conductive. In addition, like most second-generation semiconductors, silicon MOSFETs can usually be replaced by SiC versions without product redesign, highlighting how compatible SiC semiconductors are.
Energy Storage Systems
Energy storage devices, especially lithium-ion batteries, also show greater promise with semiconductor material advancements. A major hurdle for lithium-ion batteries — and by extension, EVs and renewable energies — is their weight. Developers must also grapple with the scarcity and ethics of obtaining the required minerals.
These limitations mostly relate to the electrochemistry involved, where more advanced alternatives generate much higher temperatures that are difficult to harness into electricity. However, the increased temperature thresholds of WBG semiconductors and their ability to withstand higher electric fields are helping engineers overcome these challenges to make truly green lithium-ion batteries a reality.
More advanced semiconductor materials improve battery efficiency, which:
- Extends their lifespans
- Reduces lifecycle costs
- Mitigates the impact of e-waste
Energy storage systems also become safer, and lighter-weight batteries will make the EVs themselves more efficient.
Renewable Energy Systems
These impacts are, quite naturally, extending to the renewable energy sector. Beyond storage needs, renewable energy systems also rely on specialty semiconductor materials for energy production. In fact, power electronics for renewable energies, such as photovoltaic (PV) cells and wind turbine generators, would not generate as much electricity without WBGs.
Modern PV inverters and turbine generators rely on advanced semiconductor materials to increase the efficiency of energy conversion and device operations. This, in turn, reduces maintenance costs and extends product lifecycles.
The Future of Semiconductor Technologies
Developments in advanced semiconductor materials have merged the fields of semiconductors and nanotechnology. As semiconductors become more efficient, the power electronics systems using them inevitably become more efficient, as well. This opens broad new vistas of innovation.
These developments are also leading to reduced costs and other practical benefits that will elevate the energy- and cost-efficiency of countless other technologies on the planet. The next generation of semiconductors may not be at Star Trek levels just yet. But the advancements in semiconductor materials may give us the giant leap forward we need to get there someday.
