Influence of the mesa electrode position on monolithic on-chip series-interconnect GaAs laser power converter performance

Abstract

Monolithic on-chip series-interconnect (MOS) technology is the most mature technology for the fabrication of muti-junction laser power converters. In this study, we focused on the effect of mesa electrodes prepared at different positions on the GaAs laser power converter performance. First, an optimized epitaxial structure was prepared, and then, two different structure six-junction MOS laser power converters were separately fabricated. The test results that structure1 which mesa electrode at the base layer has 41.5% efficiency compare to structure2 which at the lateral conduction layer (LCL)has 37.4% efficiency. The characteristic data statistics of the 95 samples with two structures indicated that structure1 produces a higher output power and exhibits better performance characteristics.According to the theoretical models of the two structures, the root cause is that structure1 has a lower series resistance. Additional simulated results show that when the base doping concentration is higher than 5.1 × 1016cm−3, structure1 has a smaller series resistance and better performance characteristics. According to the conclusions in this study, we can further improve the output performance of laser power converters, especially in larger area laser power converters.