Improvement of GaN-Based Device Performance by Plasma-Enhanced Chemical Vapor Deposition (PECVD) Directly Preparing h-BN with Excellent Thermal Management Characteristics

As the demand for high voltage levels and fast charging rates in the electric power industry increases, the third-generation semiconductor materials typified by GaN with a wide bandgap and high electron mobility have become a central material in technological development. Nonetheless, thermal management challenges have persistently been a critical barrier to the extensive adoption of gallium-nitride-based devices. The integration of two-dimensional materials into GaN-based applications stands out as a significant strategy for tackling heat-dissipation problems. However, the direct preparation of two-dimensional materials on gallium nitride is rather challenging. In this study, high-quality h-BN was prepared directly on GaN films using plasma-enhanced chemical vapor deposition, which revealed that the introduction of appropriately sized active sites is key to the growth of h-BN. Owing to the high in-plane thermal conductivity of h-BN, the thermal conductivity of the sample has been enhanced from 218 W·m^-1 K^-1 to 743 W·m^-1 K^-1. Ultraviolet photodetectors were constructed based on the obtained h-BN/GaN heterostructure and maintained excellent detection performance under high-temperature conditions, with detectivity and responsivity at 200 °C of 2.26 × 10¹³ Jones and 1712.4 mA/W, respectively. This study presents innovative concepts and provides a foundation for improving the heat-dissipation capabilities of GaN-based devices, thereby promoting their broader application.