Two-Dimensional Oxide Crystals with Atomic Thickness for Energy Devices and Electronics(3/3)

Two-dimensional materials, possessing atomic or molecular thickness and infinite planar length, have a lot of fascinating material properties which arise tremendous research interests. For example, graphene, carbon atoms arranged in honeycomb lattice structure, have zero effective mass of electron and hole due to its zero bandgap electronic structure and resulted in very high carrier mobility and low resistivity. Semiconducting transition metal dichalcogenides, such as MoS2, have a moderate bandgap about 1~2 eV, are more ideal candidates for making low-power-consuming 2-D transistors along with its good carrier mobility. High κ 2-D metal oxide materials exhibit more excellent performance in capacitor or gate dielectric due to higher dielectric constant than its bulk counterpart while maintain its wide bandgap properties. In this proposal, we are going to demonstrate using 2-D metal oxide atomic layer to replace conventional active materials in some electronic, such as solar cells and tunneling transistors. In first part, 2-D oxide atomic layer are used to replace the conventional electron transport layer in perovskite solar cells. Due to the atomic thickness and high dielectric properties of 2-D oxide atomic layer, electrons from perovskite can tunnel through and holes would be blocked which consequently reduce the carrier recombination and enhance the performance of perovskite solar cells. In second part, atomically-thin oxide layer are used as tunneling layer in graphene tunneling transistor to reduce the gate width, improving the speed of device and reducing the turn on voltage. Moreover, the fabrication of atomic 2-D oxide layer can be carried out by solution process at room temperature, which will largely reduce the fabrication cost and enable the deposition on flexible substrate for future electronics.