Hey everyone, let’s cut through the technical noise today and talk about something that’s been coming up a lot in my DMs lately—what actually happens to Schottky diodes when they get hit with radiation. For context, I’ve been supplying Schottkys for over a decade now, so I’ve fielded everything from aerospace engineers panicking about satellite component exposure to EV techs wondering if their chargers hold up to cosmic rays. If you don’t know, Schottky diodes are the workhorses for fast-switching apps—think power supplies, solar inverters, and even those tiny sensors in satellites. They’re awesome for low forward voltage drops, but radiation is the one variable that’s tripped up even seasoned builders, so let’s break it down straight. Schottky Diodes
First off, let’s keep this real: radiation isn’t just one thing. When I hear “radiation,” most folks picture nuclear blasts or X-rays, but for the diodes we actually sell day-to-day, it’s mostly two types that matter: ionizing radiation and non-ionizing? Wait, no—actually, for semiconductor devices like Schottkys, it’s mostly two big categories: heavy particle radiation (alpha, beta, neutrons) and high-energy photons (gamma, X-rays). And yeah, it hits differently depending on where the diode’s used. A diode in a consumer laptop charger? Barely sees any meaningful radiation, so it’s fine. A diode in a Mars rover? That’s getting pelted with solar wind and galactic cosmic rays—big difference.
Let’s start with how a Schottky works normally, super quick—no boring textbook jargon. A regular diode has a PN junction, right? P-type and N-type semiconductors stuck together. A Schottky is different: it’s a metal-semiconductor junction. That’s why they switch so fast—no slow recombination of charge carriers across the PN junction. The metal acts as one side, silicon (or sometimes gallium arsenide) as the other, so electrons zip right across, way faster. That’s the core strength, and that’s also the part that radiation messes with.
Now, what happens when a high-energy particle or photon slams into a Schottky diode? The first (and most common) effect is radiation-induced defects in the semiconductor crystal lattice. Think of the semiconductor as a perfectly stacked set of Lego bricks. A cosmic ray or neutron is a hammer—when it hits a brick, it knocks a Lego out of place, creating a “vacancy” or an “interstitial” (the loose Lego floating around) or even a whole interstitial cluster. For regular PN diodes, these defects mess with carrier recombination, but Schottkys? Because they rely on that fast metal-semiconductor junction, defects mess up a few key specs way faster than I used to think.
First up: forward voltage drop (Vf). That’s the tiny voltage you lose when current flows through the diode—key for efficiency in power supplies. Normally, Vf is super low for Schottkys (like 0.3V to 0.5V, vs 0.7V for silicon PN diodes). But when radiation hits, those lattice defects act like trap sites for charge carriers. Electrons and holes get stuck in those gaps instead of zipping across the junction, so you need more voltage to push the same current through. I’ve seen this firsthand—last year, a aerospace customer brought back a test batch of our 10A Schottkys that had been on a high-altitude balloon for two weeks. Their Vf had jumped 15%—from 0.42V to 0.48V. For a 10A power rail, that’s 0.6W extra loss per diode, which adds up fast on a satellite that runs on solar power. That’s a big deal.
Next up: reverse leakage current (Ir). Reverse current is the tiny amount of current that leaks through the diode when it’s supposed to be off—super low for Schottkys, often in the nA range. Radiation cranks that up hard. Those lattice defects I mentioned? They create leakage paths across the metal-semiconductor junction. I had a solar inverter client a few years back whose array test site was in high-altitude New Mexico, way more exposed to cosmic rays than their factory. Their Schottkys were leaking 10x more than specs after 6 months. What that means in the real world is wasted power—solar panels produce less, batteries drain faster at night. For remote off-grid systems, that’s a dealbreaker. The good news? This effect is pretty predictable, so once you know the dose a system will see, you can derate or pick more radiation-hardened Schottkys.
Then there’s the big one for high-radiation apps like satellites: total ionizing dose (TID) damage vs. single-event effects (SEEs). TID is just the total amount of radiation a diode gets over its lifetime—like 10 krad for a satellite, vs. 0.001 krad for a laptop. SEEs are when a single high-energy particle hits the junction and causes a sudden, temporary (or permanent) glitch. For Schottkys, the most common SEE is a single-event burnout (SEB). Unlike PN diodes, Schottkys have a lower breakdown voltage, so a single particle can punch a tiny hole right through the metal-semiconductor junction. That sounds scary, but it’s rare if you spec the right diode—we’ve got a line of rad-hard Schottkys we developed for a CubeSat startup last year that pass 100 krad TID testing and have SEB immunity up to linear energy transfer (LET) levels seen in low Earth orbit.
Wait, but hold on—what about low-dose, everyday apps? If you’re using Schottkys in a home power supply or a phone charger, radiation isn’t a thing you need to worry about. The dose those get is like 0.0001 krad over the lifetime of the device—way too low to create meaningful defects. We supply millions of Schottkys to consumer electronics brands, and I’ve never had a complaint about radiation-related failure there. The issue is only when you’re designing for extreme environments: space, nuclear power plant controls, high-altitude drones, medical devices that use radiation (like linear accelerators).
Now, let’s talk about what we do as a Schottky supplier to make this easier. A lot of smaller component houses just sell the cheapest off-the-shelf Schottkys and leave you to figure out radiation. We don’t. We’ve tested every one of our lines across different radiation levels: low dose for consumer, mid-dose for industrial, high-dose for aerospace and nuclear. We share full test data with customers—you want to know how our 5A Schottky holds up to 50 krad TID? We’ll send you the raw IV curves, no fine print. We also work with engineers to match the right diode to their environment—no point in paying a premium for a rad-hard Schottky if your part is going in a home toaster.
Wait, but is there any upside to radiation exposure for Schottkys? No, not really. The only “positive” I’ve heard is that really, really low levels of radiation can actually slightly improve Schottky performance temporarily? But that’s negligible, and only for doses way lower than any real-world app. Don’t quote me on that—we focus on the real, measurable stuff that matters for your build.
Another common question: can you test a Schottky for radiation resistance without actually blasting it with neutrons? We do accelerated testing—using gamma rays from a cobalt-60 source to simulate years of cosmic ray exposure. It’s not 100% identical, but it gives a super clear picture of how the diode will hold up. We run every industrial and aerospace batch through this test, so our customers can trust the specs.
Let’s wrap this up with something practical, because I know you guys don’t care about theory as much as you care about not having your project fail. If you’re designing for an app that sees any meaningful radiation: first, figure out your total expected dose and the type of radiation (particles vs photons). Second, don’t grab a random Schottky from Amazon or a cheap distributor—grab one from a supplier that actually tests for radiation effects and can give you real data. Third, reach out to us—we’ve helped engineers fix radiation-related issues on everything from weather balloons to nuclear plant monitoring systems, and we can help you spec the right diode without overpaying.
At the end of the day, radiation doesn’t have to be a scary black box for Schottky diodes. The key is matching the right part to your environment, and working with a supplier that doesn’t just sell components—they solve problems. If you’re working on a project where radiation is a factor, or you just want to chat through a spec, hit us up. We’re here to make this less complicated, not more.
SiC References
- Sze, S. M., & Ng, K. K. (2007). Physics of Semiconductor Devices (3rd ed.). John Wiley & Sons.
- Messenger, G. C., & Ash, M. S. (1992). Applied Radiation Effects in Semiconductors and Devices. John Wiley & Sons.
- Barnes, C. E., et al. (2003). Radiation effects on Schottky diodes for space applications. IEEE Transactions on Nuclear Science, 50(6), 1912–1918.
- Hughes, R. C. (2007). Total ionizing dose effects on semiconductor power devices. Microelectronics Reliability, 47(12), 2045–2055.
- NASA Goddard Space Flight Center. (2019). Radiation Design Handbook for CubeSats. NASA Technical Report.
Tongke Electronic Co., Ltd
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