Reliability of 1.5 × 1.5 mm²<b>β</b>‐Ga₂O₃ Power Diodes and Application in DC–DC Converter

High breakdown voltage and exceptional robustness make β‐Ga 2 O 3 power devices a key focus of current research. Despite growing attention to the reliability of β‐Ga 2 O 3 devices, systematic studies are still limited, and comparative analyses between different structures remain unreported. This study presents a comparative analysis of β‐Ga 2 O 3 Schottky barrier diodes (SBD) and p‐NiO/β‐Ga 2 O 3 heterojunction diodes (HJD) with mesa termination through comprehensive reliability test, including high‐temperature storage, reverse recovery, surge current, and rectification characteristics. The results indicate that the SBDs outperform in high‐frequency rectification performance up to 1 MHz, whereas the HJDs demonstrate superior high‐temperature stability of 250 °C. The surge current densities of the SBD and HJD devices reach 0.88 and 0.78 kA cm − 2 , respectively, representing the highest values reported to date. In particular, the efficiency of both the SBD and HJD devices exceeds 95% in circuit application, with SBD excelling in high‐frequency mode and HJD performing optimally in high‐temperature conditions. This study highlights the high reliability of β‐Ga 2 O 3 devices and provides valuable insights for the application under varied operating conditions.