CAJ | 학술논문

采用超晶格方法,利用射频磁控共溅射及在N2气氛中退火技术,制备了多层Ge纳米晶（Ge-ncs）镶嵌Si基复合薄膜（Ge-ncs＋SiO2/GeO2）.同时采用椭圆偏振光谱法,研究了Ge-ncs的光学性质,并用sp3紧束缚理论模式,解释了Ge-ncs带隙宽化现象.结果表明：用超晶格方法制备的多层Ge-ncs具有密度高、尺寸和位置分布均匀的优点,纳米晶平均尺寸为9.8nm.复合薄膜（Ge-ncs＋SiO2/GeO2）具有正常色散的特性,且在1 340nm处具有较强烈的吸收特性;Ge-ncs的光学带隙为0.82eV,与块体Ge材料相比,Ge-ncs吸收谱显示出0.16eV的带隙宽化.这种现象主要是由Ge-ncs中的量子限制效应导致的,采用sp3紧束缚理论模式可得到很好解释.
채용초정격방법,이용사빈자공공천사급재N2기분중퇴화기술,제비료다층Ge납미정（Ge-ncs）양감Si기복합박막（Ge-ncs＋SiO2/GeO2）.동시채용타원편진광보법,연구료Ge-ncs적광학성질,병용sp3긴속박이론모식,해석료Ge-ncs대극관화현상.결과표명：용초정격방법제비적다층Ge-ncs구유밀도고、척촌화위치분포균균적우점,납미정평균척촌위9.8nm.복합박막（Ge-ncs＋SiO2/GeO2）구유정상색산적특성,차재1 340nm처구유교강렬적흡수특성;Ge-ncs적광학대극위0.82eV,여괴체Ge재료상비,Ge-ncs흡수보현시출0.16eV적대극관화.저충현상주요시유Ge-ncs중적양자한제효응도치적,채용sp3긴속박이론모식가득도흔호해석.
Multilayered Ge nanocrystals(Ge-ncs) with high density and better uniformity embedded in composite film(Ge-ncs+SiO2/GeO2) have been prepared by a(SiO2+Ge)/(SiO2+GeO2) superlattice method magnetron co-sputtering technique and subsequent annealing in N2 ambient.The optical properties of the prepared composite film was investigated by spectroscopic ellipsometry and the band expansion of the prepared Ge-ncs was discussed in terms of the sp3 tight binding model theory.The size of the prepared Ge-ncs is 9.8 nm.The refractive index n(λ) shows a normal dispersion and the extinction coefficient k(λ) indicates a bigger absorption characteristic around 1 340 nm.The optical band gap of the prepared Ge-ncs was determined to be 0.82 eV.As compared with bulk Ge,the multilayered Ge-ncs exhibits a certain blue shift in the absorption spectrum and a band gap expansion of 0.16 eV.The band gap expansion can be well explained by quantum confinement effect as well as the sp3 tight binding model.