Comparative Temperature Dependent Evaluation and Analysis of 1.2-kV SiC Power Diodes for Extreme Temperature Applications

Considering potential applications related to superconductivity and aerospace (typically less than 100 K), in this article, the temperature dependence of silicon carbide (SiC) power diodes is systematically characterized and analyzed over a wide temperature range of 90–478 K, especially focusing on cryogenic temperature. First, the static performance degradation mechanism of SiC diodes is established in an ultrawide temperature range, including forward/reverse I-V characteristics and junction capacitance (
C_j
) characteristics. Second, the reverse recovery characteristics are achieved, including peak reverse recovery current (
I_rm
), reverse recovery charge (
Q
_rr
), and switching energy (
E
_sw
), clarifying a clearer internal relationship between reverse recovery and junction temperature. Meanwhile, the aforementioned critical parameters are further analyzed on an electrical scale with normal atmosphere temperature, including switching speed range of 62.3–2054.8 A/
μ
s, load current range of 6–30 A, and dc voltage range of 400–1000 V. Third, based on newly proposed power loss analysis method, the continuous operation performance of SiC diodes is quantified and analyzed in actual cryogenic converters. The excellent temperature dependence indicates that SiC diodes have great superiority for extreme applications. Importantly, SiC
mosfet
's body diode shows the great potential to operate as a freewheeling diode in the compact converter, especially at cryogenic temperature.