铜铟镓硒薄膜的四元叠层法制备与表征

Preparation and characterization of CIGS thin films by depositing quaternary layers

采用热蒸发沉积Ga、离子束溅射沉积Cu、In和Se,在BK7玻璃上形成Ga/Gu/In/Se四元叠层,在同一高真空环境下对四元叠层进行退火热处理,制备得到铜铟镓硒(CIGS)薄膜太阳电池吸收层材料CIGS薄膜.通过X射线衍射仪、能谱仪、扫描电子显微镜、分光光度计及四探针,测量材料的结构、组分、形貌以及光电特性.结果表明,通过精确控制热蒸发蒸镀Ga膜料的时间,实现在CuInSe2(CIS)薄膜上掺杂Ga元素,制备的CIGS薄膜均呈黄铜矿结构,当Ga的原子数分数x(Ga)=3.96%～9.26%时,衍射峰较强,结晶度较高,其中x(Ga)=4.70%,N(Ga)/(N(Ga)+N(In))=0.16时,颗粒明显,大小均匀平整,对应最大晶粒尺寸约为61.01 nm,光学带隙为1.18 eV.

Cu（ In, Ga）Se2 （CIGS） thin films used as the absorbing layer in solar cell were successfully fabricated by thermal evaporating Ga elements and ion beam sputtering Cu, In, Se continuously on BK7 glass substrates. Subsequently, quaternary layers were annealed in the same vacuum chamber and under the same vacuum environ- ment. The thin films were characterized with X-ray diffractometry（ XRD）, X-ray dispersive spectroscory（ EDS）, scanning electron microscopy（ SEM）, spectrophotometer and four-point probe technique in order to study the mi- crostructures, composition, surface morphology, optical and electrical properties, respectively. The results show that the（ CuInSe2 ） CIS thin films are Ga doped. All the thin films are mainly of chalcopyrite structure. The dif- fraction peak intensity is relatively strong when the atomic percentage of Ga ranges from 3.96% to 9.26% with good crystalline quality. When the atomic percentage of Ga is 4.70%, the grain size is uniform with relatively smooth surface. The maximum crystalline of the sample doped with Ga of 4.70% is about 61.01 nm and its opti- cal bandgap is 1.18 eV.