Transistor connected diode structures are described. In an example, the transistor connected diode structure includes a group III-N semiconductor material disposed on substrate. A raised source structure and a raised drain structure are disposed on the group III-N semiconductor material. A mobility enhancement layer is disposed on the group III-N semiconductor material. A polarization charge inducing layer is disposed on the mobility enhancement layer, the polarization charge inducing layer having a first portion and a second portion separated by a gap. A gate dielectric layer disposed on the mobility enhancement layer in the gap. A first metal electrode having a first portion disposed on the raised drain structure, a second portion disposed above the second portion of the polarization charge inducing layer and a third portion disposed on the gate dielectric layer in the gap. A second metal electrode disposed on the raised source structure.