Cross-Scale Synthesis of Organic High-k Semiconductors Based on Spiro-Gridized Nanopolymers
Dongqing Lin, Wenhua Zhang, Hang Yin, Haixia Hu, Yang Li, He Zhang, Le Wang, Xinmiao Xie, Hongkai Hu, Yongxia Yan, Haifeng Ling, Jin’an Liu, Yue Qian, Lei Tang, Yongxia Wang, Chaoyang Dong, Linghai Xie, Hao Zhang, Shasha Wang, Ying Wei, Xuefeng Guo, Dan Lu, Wei Huang
Abstract
High dielectric constants in organic semiconductors have been identified as a central challenge for the improvement in not only piezoelectric, pyroelectric, and ferroelectric effects but also photoelectric conversion efficiency in OPVs, carrier mobility in OFETs, and charge density in charge-trapping memories. Herein, we report an ultralong persistence length ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>l</mml:mi> </mml:mrow> <mml:mrow> <mml:mtext>p</mml:mtext> </mml:mrow> </mml:msub> <mml:mo>≈</mml:mo> <mml:mn>41</mml:mn> </mml:math> nm) effect of spiro-fused organic nanopolymers on dielectric properties, together with excitonic and charge carrier behaviors. The state-of-the-art nanopolymers, namely, nanopolyspirogrids (NPSGs), are synthesized via the simple cross-scale Friedel-Crafts polygridization of A 2 B 2 -type nanomonomers. The high dielectric constant ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>k</mml:mi> <mml:mo>=</mml:mo> <mml:mn>8.43</mml:mn> </mml:math> ) of NPSG is firstly achieved by locking spiro-polygridization effect that results in the enhancement of dipole polarization. When doping into a polystyrene-based dielectric layer, such a high- <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>k</mml:mi> </mml:math> feature of NPSG increases the field-effect carrier mobility from 0.20 to 0.90 cm 2 V -1 s -1 in pentacene OFET devices. Meanwhile, amorphous NPSG film exhibits an ultralow energy disorder (<50 meV) for an excellent zero-field hole mobility of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>3.94</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>3</mml:mn> </mml:mrow> </mml:msup> <mml:mtext> </mml:mtext> <mml:mtext>c</mml:mtext> <mml:msup> <mml:mrow> <mml:mtext>m</mml:mtext> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> <mml:mtext> </mml:mtext> <mml:msup> <mml:mrow> <mml:mtext>V</mml:mtext> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> <mml:mtext> </mml:mtext> <mml:msup> <mml:mrow> <mml:mtext>s</mml:mtext> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> , surpassing most of the amorphous <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>π</mml:mi> </mml:math> -conjugated polymers. Organic nanopolymers with high dielectric constants open a new way to break through the bottleneck of efficiency and multifunctionality in the blueprint of the fourth-generation semiconductors.