How to view the substitution potential of silicon carbide diodes in the new energy industry?

1, Technical advantage: Breaking through the physical limits of silicon-based devices
The core competitiveness of silicon carbide diodes lies in their material properties:

High frequency and high efficiency characteristics: The electron mobility of silicon carbide is three times that of silicon, and the bandgap width is three times that of silicon, which makes its reverse recovery time extremely short (<10ns) and reduces switching losses by more than 70%. In the motor controller of new energy vehicles, the use of silicon carbide diodes can improve system efficiency by 3% -5% and increase range by 5% -10%.
High temperature resistance and high reliability: The critical breakdown field strength of silicon carbide is 10 times that of silicon, and it can work stably in high temperature environments above 600 ℃. Its thermal conductivity is 3 times that of silicon, and its heat dissipation efficiency is significantly improved. In photovoltaic inverters, silicon carbide diodes can reduce the volume of heat dissipation modules by 40% and extend the system lifespan to over 20 years.
Miniaturization and lightweighting: High breakdown field strength allows device design to be thinner, and under the same power, the volume of silicon carbide diodes is only one-third of silicon-based devices, reducing weight by 60%. This feature is particularly important in the electric drive system of new energy vehicles, as it can free up more space for battery layout.
2, Application scenarios and alternative logic in the new energy industry
New energy vehicles: a leap from auxiliary to core
Car charger (OBC): Silicon carbide diodes achieve a conversion efficiency of 99% on an 800V high voltage platform, which is 5 percentage points higher than silicon-based devices, and the charging speed is increased by 30%. Tesla Model 3, BYD Han and other models have adopted silicon carbide power modules in bulk.
Motor controller: an inverter composed of silicon carbide diodes and MOSFETs, which can increase the motor speed to over 20000rpm and achieve a power density of over 50kW/L. The silicon carbide electric drive system equipped on NIO ET7 reduces comprehensive energy consumption by 6%.
Charging pile: Silicon carbide diodes achieve 98% energy conversion efficiency in DC fast charging piles, support 480kW overcharging power, and shorten charging time to less than 10 minutes. State Grid has launched a pilot project for standardizing silicon carbide charging piles.
Photovoltaic power generation: an efficiency revolution from centralized to distributed
String inverter: Silicon carbide diodes enable the maximum conversion efficiency of the inverter to exceed 99%, and it can still maintain an efficiency of over 98.5% in high temperature environments such as deserts and plateaus. Huawei, Sunac and other companies have launched a full silicon carbide photovoltaic inverter product line.
Micro inverter: The miniaturization characteristics of silicon carbide diodes have increased the power density of micro inverters to 1kW/L, reduced the cost of single modules by 40%, and promoted the explosion of the BIPV market.
Energy Storage System: Upgrading from Energy Transfer to Intelligent Management
Battery Management System (BMS): Silicon carbide diodes achieve 99.5% energy conversion efficiency in bidirectional DC-DC converters, reducing battery charging and discharging losses by 15% and extending cycle life by 20%. Companies such as CATL and BYD have applied it to energy storage power stations.
Grid side energy storage: Silicon carbide diodes support MW level power output in 1500V high-voltage energy storage systems, and the system response speed is improved to millisecond level, providing key support for renewable energy grid connection.
3, Market pattern: Accelerated domestic substitution and downward trend in costs
Global competitive landscape
International giants such as Wolfspeed, Infineon, and Rohm dominate the high-end market, with a global market share of 65% for silicon carbide power devices by 2024, but Chinese manufacturers are rapidly rising. Tianyue Advanced, Tianke Heda and other enterprises have achieved mass production of 6-inch substrates, and 8-inch substrates have entered the customer verification stage.
In 2024, the market size of silicon carbide diodes in China will reach 2.8 billion yuan, a year-on-year increase of 55%, of which automotive grade products account for over 60%. It is expected that by 2030, the global market share of Chinese silicon carbide diodes will increase to 35%.
Cost reduction drives substitution
The proportion of substrate cost has decreased from 70% in 2020 to 45% in 2025, and the price of 6-inch silicon carbide substrates has dropped from 5000 yuan/piece to 2000 yuan/piece, nearly three times that of silicon-based devices. With the mass production of 8-inch substrates, costs are expected to further decrease.
Domestic silicon carbide diodes are priced 30% -50% lower than imported products, and have formed a substitution advantage in cost sensitive fields such as new energy vehicles and photovoltaics. For example, the domestically produced silicon carbide module used in BYD Han EV saves 12000 yuan per vehicle compared to imported products.