Compact, highly accurate and fast optical systems for three-dimensional image acquisition are becoming increasingly important in various future relevant applications. A special optoelectronic detector that can be used for distance measurement is the Photonic Mixer Device (PMD). We developed a graphene-based PMD, which benefits from the advantages of graphene (high charge carrier mobility and broadband absorption spectrum) and results in a broadband PMD with enhanced depth resolution. Our graphene PMD has a mirror-symmetrical design and combines two photodetectors in such a way that they have a common source contact made of palladium and two separate drain contacts made of titanium. The charge carrier swing, which is the main feature of a standard PMD, is realized via two separate buried gate contacts. Two versions of the graphene PMD, one silicon-substrate based and the other glass-substrate based, were fabricated. The fabrication steps as well as measurements of the electrical behavior and the photocurrent of the manufactured graphene PMDs are presented.
|