Electronic Structures Of Peptide Fibers And Electronic Structures And Polarization Charactoristics Of Doped Bi₂WO₆

The research in inorganic semiconductor materials, devices and circuits has beenvery mature, and a full industrial chain has been set up based on inorganicsemiconductors. As new requests are required, for example, lower costs, soft structureand biological compatibility et al. the science of organic electronics has become a hotspot, and it has already replaced inorganic electronic materials in some areas. As forinorganic materials, the ferroelectric materials have been an important part inNon-volatile memories and more and more attention has been paid to this area. Bismuthoxide layered perovskite structure is researched by more and more institutions for betterpolarization retention and fatigue resistance and so on.We test the potential application of peptide fibers in organic semiconductor anddetailed analysis is performed for the theoretical model. As for the part in ferroelectrics,the doping effects on the electronic structures and ferroelectricity of Bi₂WO₆areanalyzed. The body of the paper is as follows:1. The atomic models of Gly peptide fibers and Gly peptide fiber arrays are set up.The detailed analysis on the band structures, dense of states, electron density differenceand population of these two structures reveal their potential application in organicmaterials and the inner physical principles are explained. The results are compared withformer researcher’s results, and reveal the impact on electronic structure of thedifference of atomic structure.2. The atomic models of Cys peptide fibers and Cys peptide fiber arrays are set up.The electronic structures under the impact between S side chains and the peptide bondare analyzed. The value of potential application is proposed based on the characters ofthe band structure of Cys peptide fiber arrays.3. The atomic models of Trp peptide fibers and Trp peptide fiber arrays are set up.The impact on the system electronic structure by the Indole groups and peptide bondgroups is performed. We find typical inorganic semiconductor band structure in Trppeptide fiber arrays.4. The atomic model of parraelectric and ferroelectric Bi₂WO₆are established. And we compare the difference in electronic structures and ferroelectricity. We calculated thepolarization of ferro-BWO and compare our results with former research.5. V, Nb and Ta are doped on the W site in BWO, forming Bi2W0.75V0.25O6,Bi2W0.75Nb0.25O6and Bi2W0.75Ta0.25O6. The electronic structures and polarization ofthese three structures are performed. And the decrease in band gaps and the increase inpolarization are explained theoretically. The balance between decreased band gap andincreased polarization needs to be reached in application.