GaN Negative Differential Resistance Components with Terahertz Operation Capability: From Fundamentals to Devices
Book Chapter
Pavlidis, D. (2005). GaN Negative Differential Resistance Components with Terahertz Operation Capability: From Fundamentals to Devices
. 351-386. 10.1016/B978-008044426-0/50013-4
Pavlidis, D. (2005). GaN Negative Differential Resistance Components with Terahertz Operation Capability: From Fundamentals to Devices
. 351-386. 10.1016/B978-008044426-0/50013-4
Negative differential resistance (NDR) devices are solid-state components based on the NDR principle, providing a solution for low-cost, low noise, and high power microwave radiation sources. Such devices are widely used in intrusion alarms, microwave test instruments, and automotive collision avoidance systems. Currently, these devices are fabricated on GaAs and InP that are III-V, direct bandgap semiconductor materials exhibiting NDR. Although the devices based on these materials have proven to be reliable, they are limited in power and operation frequencies because of basic material features related to the band structure and transport properties. For higher frequency and high power applications like military radar, high-speed communications, and possibly biological agent detection, it is essential for exploring other semiconductor materials. One such material that is being investigated for these applications of NDR devices is gallium nitride (GaN). GaN is a wide-bandgap semiconductor material whose velocity-field characteristics are expected to present NDR. The advantages of using GaN over GaAs and InP—in terms of increased power handling capability and higher operation frequency—are directly related to its larger intervalley energy gap and higher peak and saturation velocities. In GaN, further confirmation is required regarding the presence of a transferred-electron effect and the processing technology of GaN is in its early stages, it has a lot of potential and thus is worth investigating.
