Ta_(2)O_(5) films are deposited on fused silica substrates by electron beam evaporation method.The optical property,x-ray photoelectron spectroscopy,band gap and nanosecond laser-induced damage threshold(LIDT)of the f...Ta_(2)O_(5) films are deposited on fused silica substrates by electron beam evaporation method.The optical property,x-ray photoelectron spectroscopy,band gap and nanosecond laser-induced damage threshold(LIDT)of the films before and after annealing are studied.It is found that the existence of an oxygen vacancy results in the decrease of the transmittance,refractive index,both macroscopic band gap and microscopic band gap,and the LIDT of Ta_(2)O_(5) films.If the oxygen vacancy forms,the macroscopic band gap decreases 2%.However,when the oxygen vacancy forms the microscopic band gap decreases 73%for crystalline Ta_(2)O_(5) and 77%for amorphous Ta_(2)O_(5).The serious decrease of microscopic band gap may significantly increase the absorbance of the micro-area in Ta_(2)O_(5) films when irradiated by laser,thus the damage probability increases.It is consistent with our experimental results that the LIDT of the as-deposited Ta_(2)O_(5) films is 7.3 J/cm^(2),which increases 26%to 9.2 J/cm^(2) when the oxygen vacancy is eliminated after annealing.展开更多
Due to their particular optical characteristics,metallic island films have the potential to significantly increase the energy conversion efficiency of solar cell.We experimentally and theoretically investigated the ef...Due to their particular optical characteristics,metallic island films have the potential to significantly increase the energy conversion efficiency of solar cell.We experimentally and theoretically investigated the effect of substrate temperature on the morphologies and optical properties of the silver island films.At low temperature,below 300 ℃,as the substrate temperature increases.Compared to the films prepared at room temperature,the sizes of nanoparticles decrease and the Absorption peaks shift to shorter wavelength accompanied by an increase density resulting in a 150% Absorption efficiency.As the substrate temperature goes up to 300 ℃,nanoparticles with larger in-plan(X-Y)dimensions are formed,the number density decreases and the Absorption peaks redshift but the Absorption efficiency is still 10% higher.Numerical simulation reveals that these behaviors are a consequence of morphologies transformation.展开更多
基金Supported by the National Natural Science Foundation of China(Nos 61107080,50921002)the Natural Science Foundation of Jiangsu Province of China(No BK2011223)+3 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China(New Teachers)(No 20110095120018)the China Postdoctoral Science Foundation(No 20110491472)the National Undergraduate Innovation Experiment Programs(No 2012106)the Fundamental Research Funds for the Central Universities(No 2012QNA03).
文摘Ta_(2)O_(5) films are deposited on fused silica substrates by electron beam evaporation method.The optical property,x-ray photoelectron spectroscopy,band gap and nanosecond laser-induced damage threshold(LIDT)of the films before and after annealing are studied.It is found that the existence of an oxygen vacancy results in the decrease of the transmittance,refractive index,both macroscopic band gap and microscopic band gap,and the LIDT of Ta_(2)O_(5) films.If the oxygen vacancy forms,the macroscopic band gap decreases 2%.However,when the oxygen vacancy forms the microscopic band gap decreases 73%for crystalline Ta_(2)O_(5) and 77%for amorphous Ta_(2)O_(5).The serious decrease of microscopic band gap may significantly increase the absorbance of the micro-area in Ta_(2)O_(5) films when irradiated by laser,thus the damage probability increases.It is consistent with our experimental results that the LIDT of the as-deposited Ta_(2)O_(5) films is 7.3 J/cm^(2),which increases 26%to 9.2 J/cm^(2) when the oxygen vacancy is eliminated after annealing.
基金The Distinguished Youth Foundation of Hunan Province(03JJY1008)The Natural Science Foundation of Hunan Province(06JJ2034)
文摘Due to their particular optical characteristics,metallic island films have the potential to significantly increase the energy conversion efficiency of solar cell.We experimentally and theoretically investigated the effect of substrate temperature on the morphologies and optical properties of the silver island films.At low temperature,below 300 ℃,as the substrate temperature increases.Compared to the films prepared at room temperature,the sizes of nanoparticles decrease and the Absorption peaks shift to shorter wavelength accompanied by an increase density resulting in a 150% Absorption efficiency.As the substrate temperature goes up to 300 ℃,nanoparticles with larger in-plan(X-Y)dimensions are formed,the number density decreases and the Absorption peaks redshift but the Absorption efficiency is still 10% higher.Numerical simulation reveals that these behaviors are a consequence of morphologies transformation.
