Interface characteristics possess very important influence on the performance of thin film devices. ITO/ PTCDA/p-Si thin film device was set up with vacuum evaporation and sputter deposition method. The surface and in...Interface characteristics possess very important influence on the performance of thin film devices. ITO/ PTCDA/p-Si thin film device was set up with vacuum evaporation and sputter deposition method. The surface and interface electron states of ITO/PTCDA/p-Si were investigated by X-ray photoelectron spectroscopy （XPS） and argon ion beam etch techniques. Results indicate that at the interface of ITO/PTODA/p- Si,not only ITO/PTCDA-Si but also PDCDA-Si can produce diffusion. Moreover, the XPS spectra of each atom appear chemical shifts, and the chemical shifts of C1s and O1s are more remarkable.展开更多
对有机/无机光电探测器PTCDA/p-Si样品的表面进行得AFM扫描看出,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它缺陷引...对有机/无机光电探测器PTCDA/p-Si样品的表面进行得AFM扫描看出,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它缺陷引起的。将样品表面的XPS全谱及精细谱与表面的AFM扫描图进行对比分析,得出PTCDA在p-Si基底上的生长模式,即:PTCDA首先在缺陷处聚集,形成许多三维岛状的PTCDA晶核,然后在PTC-DA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。与硅衬底原子结合的过程为:苝环与缺陷处的Si原子结合,而酸酐基团与表面完整处的Si结合。结合时,苝环结构保持不变,而酸酐基团与Si发生化学反应,使酸酐中的C O键断开,形成O Si C和硅氧化物。对PTCDA/p-Si样品的界面的XPS全扫描谱和精细图谱进行分析后,进一步验证了PTCDA在p-Si基底上的生长模式。展开更多
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. ...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 anhydt＇ide 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.展开更多
Highly oriented voids-free 3C-SiC heteroepitaxial layers are grown onφ50mm Si (100) substrates by low pressure chemical vapor deposition (LPCVD).The initial stage of carbonization and the surface morphology of carbon...Highly oriented voids-free 3C-SiC heteroepitaxial layers are grown onφ50mm Si (100) substrates by low pressure chemical vapor deposition (LPCVD).The initial stage of carbonization and the surface morphology of carbonization layers of Si (100) are studied using reflection high energy electron diffraction (RHEED) and scanning electron microscopy (SEM).It is shown that the optimized carbonization temperature for the growth of voids-free 3C-SiC on Si (100) substrates is 1100℃.The electrical properties of SiC layers are characterized using Van der Pauw method.The I-V,C-V,and the temperature dependence of I-V characteristics in n-3C-SiC/p-Si heterojunctions with AuGeNi and Al electrical pads are investigated.It is shown that the maximum reverse breakdown voltage of the n-3C-SiC/p-Si heterojunction diodes reaches to 220V at room temperature.These results indicate that the SiC/Si heterojunction diode can be used to fabricate the wide bandgap emitter SiC/Si heterojunction bipolar transistors (HBT's).展开更多
The partial deposit films on p-silicon wafers were formed from three kinds of plating solution: chloro-platinic acid, potassium tetranitroplatinate and diammine platinium dinitrate under Nd: YAG laser irradiation. The...The partial deposit films on p-silicon wafers were formed from three kinds of plating solution: chloro-platinic acid, potassium tetranitroplatinate and diammine platinium dinitrate under Nd: YAG laser irradiation. The compositions and properties of the depositswere investigated by AES, SEM and XPS techniques. The Pt deposits have ohmic contactwith p-type silicon.展开更多
基金Project is supported by the National Natural Science Foundationof China (Grant No 60076023)
文摘Interface characteristics possess very important influence on the performance of thin film devices. ITO/ PTCDA/p-Si thin film device was set up with vacuum evaporation and sputter deposition method. The surface and interface electron states of ITO/PTCDA/p-Si were investigated by X-ray photoelectron spectroscopy （XPS） and argon ion beam etch techniques. Results indicate that at the interface of ITO/PTODA/p- Si,not only ITO/PTCDA-Si but also PDCDA-Si can produce diffusion. Moreover, the XPS spectra of each atom appear chemical shifts, and the chemical shifts of C1s and O1s are more remarkable.
文摘对有机/无机光电探测器PTCDA/p-Si样品的表面进行得AFM扫描看出,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它缺陷引起的。将样品表面的XPS全谱及精细谱与表面的AFM扫描图进行对比分析,得出PTCDA在p-Si基底上的生长模式,即:PTCDA首先在缺陷处聚集,形成许多三维岛状的PTCDA晶核,然后在PTC-DA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。与硅衬底原子结合的过程为:苝环与缺陷处的Si原子结合,而酸酐基团与表面完整处的Si结合。结合时,苝环结构保持不变,而酸酐基团与Si发生化学反应,使酸酐中的C O键断开,形成O Si C和硅氧化物。对PTCDA/p-Si样品的界面的XPS全扫描谱和精细图谱进行分析后,进一步验证了PTCDA在p-Si基底上的生长模式。
文摘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 anhydt＇ide 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.
文摘Highly oriented voids-free 3C-SiC heteroepitaxial layers are grown onφ50mm Si (100) substrates by low pressure chemical vapor deposition (LPCVD).The initial stage of carbonization and the surface morphology of carbonization layers of Si (100) are studied using reflection high energy electron diffraction (RHEED) and scanning electron microscopy (SEM).It is shown that the optimized carbonization temperature for the growth of voids-free 3C-SiC on Si (100) substrates is 1100℃.The electrical properties of SiC layers are characterized using Van der Pauw method.The I-V,C-V,and the temperature dependence of I-V characteristics in n-3C-SiC/p-Si heterojunctions with AuGeNi and Al electrical pads are investigated.It is shown that the maximum reverse breakdown voltage of the n-3C-SiC/p-Si heterojunction diodes reaches to 220V at room temperature.These results indicate that the SiC/Si heterojunction diode can be used to fabricate the wide bandgap emitter SiC/Si heterojunction bipolar transistors (HBT's).
文摘The partial deposit films on p-silicon wafers were formed from three kinds of plating solution: chloro-platinic acid, potassium tetranitroplatinate and diammine platinium dinitrate under Nd: YAG laser irradiation. The compositions and properties of the depositswere investigated by AES, SEM and XPS techniques. The Pt deposits have ohmic contactwith p-type silicon.
