Structural and electrical characterization of spin-coated polyurea thin films
Structural and electrical characterization of spin-coated polyurea thin films
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DOI：
10.1016/j.polymer.2015.10.005
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发表时间：
2015-11
期刊：
影响因子：
4.6
通讯作者：
M. Morimoto;Y. Koshiba;M. Misaki;K. Ishida
中科院分区：
文献类型：
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作者：
M. Morimoto;Y. Koshiba;M. Misaki;K. Ishida
聚脲薄膜的制备受到在大多数有机溶剂中溶解性差的阻碍。我们制备了旋涂的聚脲薄膜，并研究了薄膜的结构和电学性能。初生膜表面粗糙，结晶度较高，晶粒尺寸为4.5 nm，而熔融淬火膜表面光滑，结晶度较低，晶粒尺寸为2.7 nm。在高于溶剂沸点的温度下，残留溶剂保留在膜中。淬火的聚脲膜表现出大的电流峰值，源自激活的杂质电荷从残留溶剂中的电流密度-电场曲线。热释电系数为4.13 μC/m2 K。聚脲膜保持热电性，即使在施加电场后，从而表现出在热释电器件与退火，以去除杂质电荷的潜在的适用性。
Thin-film fabrication of polyurea is hindered by poor solubility in most organic solvents. We fabricated spin-coated thin films of polyurea and investigated the structural and electrical properties of the films. The as-spun films had rough surfaces and relatively high crystallinity with 4.5 nm grains, while melt-quenched films were smooth and lower in crystallinity with 2.7 nm grains. Residual solvent remained in the films at temperatures above the boiling point of the solvent. The quenched polyurea films exhibited large current peaks originating from activated impurity charges from the residual solvent in the current density-electric field curves. The pyroelectric coefficient of the spin-coated polyurea films was estimated to be 4.13 μC/m2K. The polyurea films maintained pyroelectricity even after the application of an electric field, thereby exhibiting potential applicability in pyroelectric devices with annealing to remove the impurity charges.