Phase-controlled large-area growth of MoTe2 and MoTe2-xOx/MoTe2 heterostructures for tunable memristive behavior

Two dimensional layered materials show great potential in memristor applications. MoTe2 shows unique properties and is an important 2D material. However, MoTe2- based memristor has been rarely studied so far. Herein, a facile method is developed to control phase in large area MoTe2 and MoTe2-xOx/MoTe2 heterostructures by precursor thickness in chemical vapor deposition. The memristive behavior of MoTe2 is highly influenced by phase and oxidization states in MoTe2-xOx/MoTe2 heterostructures. The original 2H and 1 T' MoTe2 doesn't have memristive property while the surface oxidized 2H-MoTe2 based MoTe2-xOx/MoTe2 heterostructures behave excellent and stable memristive behavior for at least 3000 cycles. 1 T' -MoTe2 based heterostructures still show no memristive behavior. In addition, we compare the effect of metal electrode (Ag electrode and Al electrode) on heterostructures based memristor. The pulse tests about memristor from oxidized 2H-MoTe2 based heterostructures show a good mimic of biological synapses in neuromorphic system.