There are disclosed herein various implementations of a III-Nitride bidirectional device. Such a bidirectional device includes a substrate, a back channel layer situated over the substrate, and a device channel layer and a device barrier layer situated over the back channel layer. The device channel layer and the device barrier layer are configured to produce a device two-dimensional electron gas (2DEG). In addition, the III-Nitride bidirectional device includes first and second gates formed on respective first and second depletion segments situated over the device barrier layer. The III-Nitride bidirectional device also includes a back barrier situated between the back channel layer and the device channel layer. A polarization of the back channel layer of the III-Nitride bidirectional device is substantially equal to a polarization of the device channel layer.