Gold nanoparticle density-multiplication by tuning block copolymer self-assembly processes toward increased charge storage

Abstract

We describe a simple and versatile approach for enhanced nanoparticle density multiplication through the block copolymer self-assembly technique for application in memory devices. Templates of block copolymers with functional groups directed the selective electrostatic self-assembly of the pre-formed gold nanoparticles to form gold nanocluster arrays. By simply increasing the density of the polymer templates by manipulating the spin coating conditions, a lateral increase in the nanoparticle density is observed. The significance of the particle density multiplication was best observed when they were used as charge storage centers in flash memories. Minimization of the pitch (or maximization of the template density) resulted in a maximum memory window of about 1.63 V, with a charge trap state density of 4.93 Â 10 11 cm À2 in the gold nanocluster arrays. The reported approach offers exciting opportunities to fabricate multicomponent nanostructure-based memory devices tailored for enhanced memory performance. In addition, the nanoparticle density can be increased significantly further when combined systematically with the hierarchical block copolymer self-assembly approach.

Three-Dimensional Nanoporous Metal Structures from Poly(2-vinylpyridine)-block-Poly(4-vinylpyridine) Copolymer Thin Film

“…Block copolymers (BCPs) have been widely studied because of their self-assembled nature into various periodic nanoscale structures, for instance, lamellae, cylinders, spheres, and gyroids. − Particularly, when metal precursors are coordinated with one of the blocks in BCP, such as poly­(2-vinylpyridine) (P2VP), poly­(4-vinylpyridine) (P4VP), or poly­(ethylene oxide), these can be used for fabrication of a 2D metal nanopattern, − nanoporous structures, , photonic − and memory devices, , and cell adhesion . In addition, metal oxide nanostructures are easily prepared by sequential infiltration synthesis (SIS) − when metal oxide precursors are interacting with one of the microdomains in block copolymers.…”

Highly Reliable Charge Trap‐Type Organic Non‐Volatile Memory Device Using Advanced Band‐Engineered Organic‐Inorganic Hybrid Dielectric Stacks

“…Thanks to the outstanding electrical strength and charge trapping properties of the ultra‐thin hybrid dielectrics, the endurance of the CT‐ONVM devices outperformed other ONVM devices. [ 7–37 ]…”

“…In addition, there are issues with the non‐conformality and non‐uniformity of the metal NPs fabrication. [ 29–37 ] There are also studies in which Oxide was proposed as CTL instead of conducting material. [ 38 ]…”

Nanostructured materials for non-volatile organic transistor memory applications

“…An alternative approach is to use embedded conducting nanoparticles in an insulating gate dielectric matrix. [26][27][28] The advantage of nanoparticle/ nanostructure-based memory transistors is the tunable density of traps in the dielectric, while the morphology/surface energy is maintained, since the semiconductor/dielectric interface remains the same. The discreteness of the charge storage on the nanoparticles also reduces the release of charge in the event of localized defects in the dielectric layer.…”