Monolithic Integration of GaN-based Optocoupler

This paper proposed a GaN-based optocoupler chip with monolithic integration. It differs from commercial photodiode optocouplers consisting of at least two coupled chips. This study monolithically integrated a photodiode and a light emitting diode on a sapphire substrate as a single chip. This approach makes the optical transmission of signal in a thin sapphire substrate with a micro-meter scale transmission path reducing light loss. In the experiment, the measurement results showed that the proposed chip has a great current transfer ratio. It meets commercial specifications and provides a more efficient optocoupler manufacturing solution.