The macroscopic alignment of conjugated polymers with low grain boundary is essential to carrier transport. During film forming process, the match between contact line receding velocity and the critical alignment velo...The macroscopic alignment of conjugated polymers with low grain boundary is essential to carrier transport. During film forming process, the match between contact line receding velocity and the critical alignment velocity is essential to get the alignment polymer film. In this paper, the contact line receding velocity of a D-A conjugated polymer film, isoindigo and bithiophene（IIDDT-C3）, was adjusted by solvent vapor content and film-formation temperature. Only when solvent vapor content was 0.3 m L and the film-formation temperature was 90C, the contact line receding velocity was in accordance with the critical alignment velocity, and the highest degree of alignment was attained in the IIDDT-C3 film, with the dichroic ratio up to 4.08. Fibers were aligned parallel with the direction of the contact line receding and the molecules of IIDDT-C3 adopted an edge-on orientation with the backbone parallel with the direction of fiber long axis. The p-p stacking distance between adjacent molecules was 3.63 ？.展开更多
Low metal-graphene contact resistance is important in making high-performance graphene devices.In this work,we demonstrate a lower specific contact resistivity of Au0.88Ge0.12/Ni/Au-graphene contact compared with Ti/A...Low metal-graphene contact resistance is important in making high-performance graphene devices.In this work,we demonstrate a lower specific contact resistivity of Au0.88Ge0.12/Ni/Au-graphene contact compared with Ti/Au and Ti/Pt/Au contacts.The rapid thermal annealing process was optimized to improve AuGe/Ni/Au contact resistance.Results reveal that both pre- and post-annealing processes are effective for reducing the contact resistance.The specific contact resistivity decreases from 2.5 × 10^-4 to 7.8 × 10^-5 Ω·cm^2 by pre-annealing at 300 ℃ for one hour,and continues to decrease to 9.5 × 10^-7 H·cm2 after post-annealing at 490 ℃ for 60 seconds.These approaches provide reliable means of lowering contact resistance.展开更多
Hole transporting layer(HTL) free organometal halide perovskite solar cells have shown great promise in simplifying device architecture,fabrication process and enhancing stability.However,the simple elimination of the...Hole transporting layer(HTL) free organometal halide perovskite solar cells have shown great promise in simplifying device architecture,fabrication process and enhancing stability.However,the simple elimination of the HTL from the standard sandwiched configuration suffers from relatively poor device performance;additionally,the mechanism of the HTL-free perovskite solar cell is still unclear.Herein,we applied a one-dimensional modeling program wxAMPS to investigate the planar HTL-free perovskite solar cells by adjusting the absorber thickness,doping and the absorber/back contact band alignment.The simulation results reveal the importance of the moderate absorber thickness as well as the p-doping perovskite rather than intrinsic as in sandwich structure to the overall device efficiency.In the meanwhile,reducing the mismatching of the absorber/back contact by using higher work function back contact material in replacement of commonly utilized Au electrode is more favorable to improve the device performance.Through optimizing,high performance HTL-free perovskite solar cell with efficiency approaching 17%could be achieved.This study is helpful in providing theoretical guidance for the design of HTL-free perovskite solar cells.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21334006,51573185,21474113)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB12020300)OTFT National Key R&D Program of“Strategic Advanced Electronic Materials”(No.2016YFB0401100)
文摘The macroscopic alignment of conjugated polymers with low grain boundary is essential to carrier transport. During film forming process, the match between contact line receding velocity and the critical alignment velocity is essential to get the alignment polymer film. In this paper, the contact line receding velocity of a D-A conjugated polymer film, isoindigo and bithiophene（IIDDT-C3）, was adjusted by solvent vapor content and film-formation temperature. Only when solvent vapor content was 0.3 m L and the film-formation temperature was 90C, the contact line receding velocity was in accordance with the critical alignment velocity, and the highest degree of alignment was attained in the IIDDT-C3 film, with the dichroic ratio up to 4.08. Fibers were aligned parallel with the direction of the contact line receding and the molecules of IIDDT-C3 adopted an edge-on orientation with the backbone parallel with the direction of fiber long axis. The p-p stacking distance between adjacent molecules was 3.63 ？.
基金Project supported by the National Natural Science Foundation of China(Grant No.61376065)the Science and Technology Project of Suzhou,China(Grant No.ZXG2013044)
文摘Low metal-graphene contact resistance is important in making high-performance graphene devices.In this work,we demonstrate a lower specific contact resistivity of Au0.88Ge0.12/Ni/Au-graphene contact compared with Ti/Au and Ti/Pt/Au contacts.The rapid thermal annealing process was optimized to improve AuGe/Ni/Au contact resistance.Results reveal that both pre- and post-annealing processes are effective for reducing the contact resistance.The specific contact resistivity decreases from 2.5 × 10^-4 to 7.8 × 10^-5 Ω·cm^2 by pre-annealing at 300 ℃ for one hour,and continues to decrease to 9.5 × 10^-7 H·cm2 after post-annealing at 490 ℃ for 60 seconds.These approaches provide reliable means of lowering contact resistance.
基金supported partially by the National High-tech R&D Program of China(863 Program,2015AA034601)the National Natural Science Foundation of China(91333122,61204064,51202067,51372082,51402106 and 11504107)+1 种基金PhD Programs Foundation of Ministry of Education of China(20120036120006 and 20130036110012)Par-Eu Scholars Program,and the Fundamental Research Funds for the Central Universities
文摘Hole transporting layer(HTL) free organometal halide perovskite solar cells have shown great promise in simplifying device architecture,fabrication process and enhancing stability.However,the simple elimination of the HTL from the standard sandwiched configuration suffers from relatively poor device performance;additionally,the mechanism of the HTL-free perovskite solar cell is still unclear.Herein,we applied a one-dimensional modeling program wxAMPS to investigate the planar HTL-free perovskite solar cells by adjusting the absorber thickness,doping and the absorber/back contact band alignment.The simulation results reveal the importance of the moderate absorber thickness as well as the p-doping perovskite rather than intrinsic as in sandwich structure to the overall device efficiency.In the meanwhile,reducing the mismatching of the absorber/back contact by using higher work function back contact material in replacement of commonly utilized Au electrode is more favorable to improve the device performance.Through optimizing,high performance HTL-free perovskite solar cell with efficiency approaching 17%could be achieved.This study is helpful in providing theoretical guidance for the design of HTL-free perovskite solar cells.
