CAJ | 학술논문

对有机/无机光电探测器PTCDA/p-Si样品表面进行AFM测试,结果表明PTCDA呈岛状生长,各岛成圆丘状,岛的分布不均匀,PTCDA层中存在大量缺陷.原因是p-Si(100)衬底的表面原子悬挂键的作用,使硅原子横向移动满足键合需要形成台阶和其他缺陷.得出PTCDA在p-Si基底上的生长模式为:PTCDA首先在缺陷处聚集,形成许多三维岛状的PTCDA晶核,然后在PTCDA离域大π键的作用下,相邻的两层PTCDA分子存在一定程度的交叠,最终形成岛状结构.
대유궤/무궤광전탐측기PTCDA/p-Si양품표면진행AFM측시,결과표명PTCDA정도상생장,각도성원구상,도적분포불균균,PTCDA층중존재대량결함.원인시p-Si(100)츤저적표면원자현괘건적작용,사규원자횡향이동만족건합수요형성태계화기타결함.득출PTCDA재p-Si기저상적생장모식위:PTCDA수선재결함처취집,형성허다삼유도상적PTCDA정핵,연후재PTCDA리역대π건적작용하,상린적량층PTCDA분자존재일정정도적교첩,최종형성도상결구.
AFM scanning images of the surface of a PTCDA/p-Si specimen used in an organic/inorganic photodetector show that PTCDA grows in island shapes that are poorly distributed, with each island shaped like a round hillock. The images also show that there exist enormous defects in the PTCDA layer due to pedestal sites and other defects that appear when Si atoms shift transversely, and that the bonding condition is satisfied by the action of atom suspension bonding at the surface of the Si substrate. We infer the growth mode of PTCDA deposited onto p-Si substrates as follows. First,PTCDA molecules assemble at the defects to form three-dimensional island-like PTCDA crystal nuclei, and then by the action of delocalized big π bonding, two adjacent layers of PTCDA molecules overlap to some extent and finally island-like structures form. The PTCDA molecules and Si substrate combine by a process of the combination of benzene rings with Si atoms at the defects and of acid anhydride radicals with Si atoms at the perfect fraction of the surface. In the course of combination, although the structure of the benzene rings does not change, the chemical reaction of acid anhydride radicals and Si occurs to break off the C=O bond in the acid anhydride, and then C-Si-O and silicon oxide might be produced.