Laser power converter architectures based on 3C-SiC with efficiencies > 80%
High power laser transmission technology is based on energy transfer through a monochromatic laser onto a photovoltaic receiver avoiding the limitations of conventional wiring. Current technology, headed by GaAs-based devices, faces two limitations: the intrinsic entropic losses and the degradation at high input power densities due to ohmic losses. We propose two novel laser power converters focused on overcoming these limitations. We use 3C-SiC as base material because of its high band-gap (2.36 eV) and its excellent crystallographic properties in order to reduce the entropic losses. Also, the current decreases due to the inherent flux reduction of high energy photons. To minimize ohmic losses we explore a recently proposed vertical architecture, which can significantly reduce series resistance around two orders of magnitude (~10 -5 Ω·cm 2 ). Furthermore, we also implement 3C-SiC in a conventional horizontal architecture to show the advantage of increasing the energy gap to reduce the ohmic losses. The two laser power converters obtain efficiencies above the state-of-the-art (87.4% at 3000 W cm -2 for the vertical architecture and 81.1% at 100 W cm -2 for the horizontal architecture) Taking this into account, the new devices open a new route for ultra-high efficiency remote powered systems.
keywords: laser power converters, 3C-SiC, wireless power transfer, high power densities