Third-generation Semiconductor Development from the Perspective of Photovoltaic Energy Storage Applications

With the continuous deterioration of the global environment and the exhaustion of fossil fuel energy, countries around the world are looking for new energy sources suitable for human survival and development. The construction of photovoltaic energy storage projects is an important measure to implement energy transformation. Third-generation semiconductors have the characteristics of high frequency, high power, high voltage resistance, high temperature resistance, and radiation resistance, which can promote highly efficient, highly reliably, and low cost of photovoltaic energy storage inverters and the green and low-carbon development of energy.

SiC will be widely used in high-power string/central inverters, while GaN is more suitable for household micro-inverters

As the photovoltaic industry enters the era of “large components, large inverters, large-span brackets, and large strings,” the voltage level of photovoltaic power plants has increased from 1000V to over 1500V and high-voltage SiC power components will be used extensively in string and centralized inverters. For residential micro-inverters with a power of up to 5kW, GaN power components have more advantages. Not only can they significantly improve overall conversion efficiency, effectively reduce the levelized cost of energy (LCOE), but also allow users to easily build smaller, lighter, and more reliable inverters.

Key SiC substrates are crucial to the development of third-generation semiconductors and major manufacturers are competing to get to market

SiC substrate is regarded as the core raw material of third-generation semiconductors. Its crystal growth is slow and process technology complex. Mass production is not easy. Conductive substrates can produce SiC power electronic components while semi-insulating substrates can be used for the fabrication of GaN microwave radio frequency components. In addition, due to the high difficulty of substrate preparation, its value is relatively high. The cost of SiC substrate accounts for approximately 50% of the total cost of components which demonstrates its importance in the industrial chain.

At present, the supply of the global SiC market is firmly in the hands of substrate manufacturers. Wolfspeed, II-VI and SiCrystal (subsidiary of ROHM) together account for nearly 90% of shipments. IDM manufacturers such as Infineon, STM, and Onsemi are actively developing upstream SiC substrates and expect to take full advantage of the supply chain to strengthen their competitiveness. Everyone wants to get a piece of the pie, so the battle for SiC substrates will become more and more fierce, but the wait will not be long to see where the industry eventually goes in coming years.

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