A Q-switched ytterbium-doped fiber laser （YDFL） is proposed and demonstrated using a newly developed multi-walled carbon nanotubes polyethylene oxide （MWCNTs-PEO） film as a passive saturable absorber （SA）. The s...A Q-switched ytterbium-doped fiber laser （YDFL） is proposed and demonstrated using a newly developed multi-walled carbon nanotubes polyethylene oxide （MWCNTs-PEO） film as a passive saturable absorber （SA）. The saturable absorber is prepared by mixing the MWCNTs homogeneous solution into a dilute PEO polymer solution before it is left to dry at room temperature to produce thin film. Then the film is sandwiched between two FC/PC fiber connectors and integrated into the laser cavity for Q-switching pulse generation. The laser generates a stable pulse operating at wavelength of 1060.2 nm with a threshold pump power of 53.43 mW. The YDFL generates a stable pulse train with repetition rates ranging from 7.92 to 24.27 kHz by varying 980-nm pump power from 53.42 to 65.72 mW. At 59.55-mW pump power, the lowest pulse width and the highest pulse energy are obtained at 12.18 μs and 143.5 n J, respectively.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 Ministry of Higher Education under ERGS Grant scheme No.ER012-2012A
文摘A Q-switched ytterbium-doped fiber laser （YDFL） is proposed and demonstrated using a newly developed multi-walled carbon nanotubes polyethylene oxide （MWCNTs-PEO） film as a passive saturable absorber （SA）. The saturable absorber is prepared by mixing the MWCNTs homogeneous solution into a dilute PEO polymer solution before it is left to dry at room temperature to produce thin film. Then the film is sandwiched between two FC/PC fiber connectors and integrated into the laser cavity for Q-switching pulse generation. The laser generates a stable pulse operating at wavelength of 1060.2 nm with a threshold pump power of 53.43 mW. The YDFL generates a stable pulse train with repetition rates ranging from 7.92 to 24.27 kHz by varying 980-nm pump power from 53.42 to 65.72 mW. At 59.55-mW pump power, the lowest pulse width and the highest pulse energy are obtained at 12.18 μs and 143.5 n J, respectively.
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.
