Research of Bio-nano Display using Ferritin Protein

在玻璃或塑料衬底上制备的多晶硅薄膜因其在平板显示器或未来显示器(如面板上系统)的薄膜晶体管(TFT)中的应用而备受关注。在本研究中，我们提出了一种利用生物技术获得高质量多晶硅薄膜的新方法。作为硅晶化的核心，铁蛋白的镍核直径为7 nm，采用自下而上的方法吸附在a-Si薄膜表面。通过调节a-Si薄膜上铁蛋白的浓度，控制Ni核密度，实现a-Si薄膜的固相晶化。控制晶核的a-Si薄膜在10min内加热到550℃，然后在氮气气氛中在快速热分析炉中热处理25h。快速加热抑制了自然晶核的产生，多晶硅的生长是从NiSi_2的控制晶核横向进行的。据报道，Ni/a-Si→NiSi_2，…的激活能较多的a-Si→晶态硅和天然核的产生分别为1.45、2.7和4.4 eV。因此，我们估计在550℃下的快速加热和连续退火促进了NiSi2的反应，从而促进了多晶硅的晶体生长。此外，为了检查晶体的尺寸和晶体取向，进行了电子背散射分析。“颗粒”被定义为具有相同晶体取向和相同相的区域。测绘图像表明，在密度为10^&lt；11&gt；cm^&lt；-2&gt；时，未观察到明确的颗粒，因此，微晶结构占主导地位。对于密度为10^&lt；10&gt；cm^&lt；-2&gt；的薄膜，确定了颗粒和微晶结构的混合体。而芯层密度为10~(-9)cm~(-2)~(-2)的薄膜，有一定的颗粒存在，且大小均匀。在所有的样品中，颗粒的取向都是随机的。以此为参照物制备的无芯薄膜无颗粒。根据粒度分布估计的平均粒度分别为0.36am、0.48it m和3.06μm。因此，随着磁芯密度的降低，晶粒度显著增大。较少

Polycrystalline silicon (poly-Si) films fabricated on glass or plastic substrates have attracted much attention due to their applications in thin-film transistors (TFT) for flat-panel displays or future displays, such as a system-on-panel. In this study, we propose a new method utilizing biotechnology to obtain high-quality poly-Si thin films. As the nucleus of silicon crystallization, the Ni core of ferritin with a diameter of 7 nm was adsorbed on the surface of a-Si films by a bottom-up process. By adjusting the density of ferritin on the a-Si film, we controlled the Ni nucleus density and performed the solid-phase crystallization of the a-Si film.The a-Si film with a controlled crystal nucleus was heated up to 550℃in 10 min and then annealed for 25 h in N_2 ambient in an RTA furnace. Rapid heating suppresses the generation of a natural nucleus and poly-Si growth proceeds laterally from the controlled nucleus of NiSi_2. It is reported that the activation energies of Ni/a-Si → NiSi_2, … More a-Si → crystalline Si, and the generation of a natural nucleus are 1.45, 2.7, and 4.4eV, respectively. Therefore, it is estimated that the rapid heating and continuous annealing at 550℃ enhanced the reaction of NiSi_2 dominantly, thus the crystal growth of poly-Si proceeded.Furthermore, to examine grain size and crystalline orientation, EBSD analysis was performed. The "grains" were defined as the regions with the same crystallographic orientations and the same phases. Mapping images showed that definite grains were not observed at a density of 10^<11>cm^<-2>, therefore, the microcrystalline structure was dominant. For the film with a density of 10^<10>cm^<-2>, a mixture of grains and a microcrystalline structure was confirmed. However, for the film with a core density of 10^9cm^<-2>, definite grains were confirmed and their size was uniform. The orientations of the grains were random in all samples. The film without cores prepared as reference had no grains. The average grain sizes estimated from the size distribution, were 0.36 a m, 0.48 it m and 3.06 μm for the core densities of 10^<11>, 10^<10> and 10^9 cm^<-2>, respectively. Thus, grain size increased markedly with decreasing core density. Less