Controlling Crystallite Orientation of Diketopyrrolopyrrole‐Based Small Molecules in Thin Films for Highly Reproducible Multilevel Memory Device: Role of Furan Substitution

Abstract

For the organic memory device with vertically arranged electrodes, controlling the film‐packing to achieve highly oriented crystallite arrangement is critical but challenging for obtaining the satisfied performance. Here, the effect of backbone planarity on the crystallite orientation is studied. Two diketopyrrolopyrrole‐based small molecules (NI2PDPP and NI2FDPP) are synthesized with increasing planarity by furan substitution for phenyl rings. Upon thin‐film analysis by atomic force microscopy, X‐ray diffraction, and grazing‐incidence small‐angle X‐ray scattering, the orientations of these crystallites are demonstrated to be well controlled through tailoring molecular planarity. The highly planar NI2FDPP in film prefers out‐of‐plane crystallite orientation with respect to the substrate normal while the nonplanar NI2PDPP displays less ordered packing with a broad orientation distribution relative to the substrate. As a result, NI2FDPP‐based memory device exhibits superior multilevel performance. More importantly, the oriented crystallite arrangement favors uniformity in NI2FDPP thin film, thus, the device displays higher reproducibility of memory effects. This study provides an effective synthetic strategy for designing multilevel memory materials with favorable crystallite orientation.

Inserting Thienyl Linkers into Conjugated Molecules for Efficient Multilevel Electronic Memory: A New Understanding of Charge‐Trapping in Organic Materials

“…We found that bromination with liquid Br 2 was more reliable than at ypical substitution reactionw ith N-bromosuccinimide( NBS). [16] Following the completion of the bromination reactions, the intermediates could be directly used without furtherp urification. These compounds were characterizedb yN MR spectroscopy.I fa ppended with long side chains, all three final products were soluble in commono rganic solvents, such as CHCl 3 ,t oluene, and orthodichlorobenzene.…”

Recent Advances of Flexible Data Storage Devices Based on Organic Nanoscaled Materials

“…One of the most important ingredients is the data storage component. Therefore, tremendous efforts focus on the investigation of new flexible memories which own nonvolatile capability, high‐density storage, fast switching, and reliable endurance property …”

Improving Memory Performances by Adjusting the Symmetry and Polarity of O‐Fluoroazobenzene‐Based Molecules

“…[1][2][3][4][5][6][7][8] Amongt he variety of organic materials used, small molecules show the meritso fw ell-definedm olecular structures, reproducible preparation,f acile purification, and easy functionalization. [12][13][14][15][16][17] Several kinds of molecular dyes have been reported for applications in electronic memory. [12][13][14][15][16][17] Several kinds of molecular dyes have been reported for applications in electronic memory.…”

“…[9][10][11] Moreover, organic molecules were the most promising in devicem iniaturization and three-dimensional architecture. [12][13][14][15][16][17] Several kinds of molecular dyes have been reported for applications in electronic memory. [10,[18][19][20][21] For instance, the azobenzene group is widely adopted in molecular skeletons owing to its excellent photoelectric properties.…”