Embodiments of the disclosure described herein comprise a tunneling field effect transistor (TFET) having a drain region, a source region having a conductivity type opposite of the drain region, a channel region disposed between the source region and the drain region, a gate disposed over the channel region, and a heterogeneous pocket disposed near a junction of the source region and the channel region. The heterogeneous pocket comprises a semiconductor material different than the channel region, and comprises a tunneling barrier less than the bandgap in the channel region and forming a quantum well in the channel region to in crease a current through the TFET transistor when a voltage applied to the gate is above a threshold voltage.