Centimetre-scale single crystal α-MoO3: oxygen assisted self-standing growth and low-energy consumption synaptic devices

High-density storage and neuromorphic devices based on 2D materials are hindered by large-scale growth. Moreover, the lack of a mature mechanism makes it difficult to obtain high-quality single crystals in large-scale 2D materials. In this work, we prepared a centimeter-scale single crystal alpha-MoO(3)via an oxygen assisted substrate-free self-standing growth method and mechanism and constructed high-performance synaptic devices based on the centimeter-scale alpha-MoO3. The oxygen assisted growth mechanism of alpha-MoO3 was developed from the periodic bond chain theory. The large-scale alpha-MoO3 is up to 2 cm and exhibits high homogeneity and single crystalline characteristic. Furthermore, with an optimized oxygen partial pressure (18%), the centimeter-scale alpha-MoO3 makes the as-prepared memristor achieve continuous conductance modulation. Moreover, the trap-controlled electron conducting mechanism of the memristor was demonstrated through I-V curve fitting analysis at various temperatures, in which the high resistance state section demonstrates space-charge-limited conduction (SCLC) mode. Moreover, the as-prepared alpha-MoO3 memristors exhibit low-energy consumption and well emulate the essential synaptic behaviors including excitatory/inhibitory postsynaptic current, paired-pulse facilitation and long-term plasticity.

Automated summary

In this study, a centimeter-scale single crystal alpha-MoO3 was prepared using an oxygen assisted substrate-free self-standing growth method and mechanism, and high-performance synaptic devices were constructed based on this material. The oxygen assisted growth mechanism of alpha-MoO3 was developed from the periodic bond chain theory, and the resulting large-scale alpha-MoO3 exhibited high homogeneity and single crystalline characteristic. With an optimized oxygen partial pressure, the centimeter-scale alpha-MoO3 enabled continuous conductance modulation in the prepared memristor. Moreover, the as-prepared alpha-MoO3 memristors demonstrated low-energy consumption and successfully emulated essential synaptic behaviors.