Optimized Power Semiconductors for the Power Electronics Based HVDC Breaker Application In the field of power electronics applications, advances in high voltage semiconductor devices have led specifically over the past few decades to tremendous improvements in terms of power handling capability and control. We focus in this paper on the recent developments with regard to optimizing thepower semiconductor for the solid state HVDC breaker for HVDC grid applications. One of the traditional approaches for the development of power semiconductors is to achieve full integration of the active power semiconductor switch and the anti-parallel freewheeling diode. The main aim for such a trend is to obtain higher power densities and more compact systems while at the same time simplifying the component manufacturability by eliminating the need for a separate anti-parallel diode. Recent development efforts over the past few years targeted a fully integrated high voltage and high current IGBT and diode structure on a single chip. As a result, an RC-IGBT type device was realized recently and referred to as the Bi-mode Insulated Gate Transistor BIGT. The BIGT was designed in accordance with the latest IGBT design concepts while fully incorporating an optimized integrated anti-parallel diode in the IGBT structure. This paper will mainly focus on the application of the BIGT especially for thepower electronics based Hybrid HVDC breaker application while presenting an overview of the recent advancements from the device design and performance viewpoint. Recent experimental data obtained from tests carried out on prototype samples will also be presented.