Abstract: Most electronic materials typically exhibit a single majority carrier type, either electrons or holes, uniformly along all directions of the crystal. These n-type and p-type regions are then integrated together to create virtually all modern electronic and energy-harvesting devices. However, layered materials have different orbitals involved in in-plane and cross-plane bonding, which can lead to either dominant n-type or p-type conduction depending on the direction of conduction, a phenomenon we refer to as“goniopolarity”.  Here, we will establish the origin of this exotic behavior and the chemical design principles for creating new goniopolar materials, which has allowed us to experimentally expand the number of known compounds with this phenomenon. Finally, we will show how the inherent charge separation in goniopolar materials can be exploited to overcome inefficiencies in electronic and energy harvesting technologies ranging from thermoelectrics to photocatalysis.