Li Jian, Du Hui, Yarbrough John, Norman Andrew, Jones Kim, Teeter Glenn, Terry Fred Lewis, Levi Dean
National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401, USA.
Opt Express. 2012 Mar 12;20 Suppl 2:A327-32. doi: 10.1364/OE.20.00A327.
A polycrystalline Cu2ZnSnS4 thin film was deposited on fused quartz by co-evaporation. The selected thickness was ~100 nm to avoid artifacts in its optical properties caused by thicker as-grown films. The composition and phase of the film were checked with x-ray fluorescence, Raman shift spectroscopy, scanning transmission electron microscopy, and energy dispersive x-ray spectroscopy. An improved spectroscopic ellipsometry methodology with two-side measurement geometries was applied to extract the complex dielectric function ε = ε1 + iε2 of the Cu2ZnSnS4 thin film between 0.73 and 6.5 eV. Five critical points were observed, at 1.32 (fundamental band gap), 2.92, 3.92, 4.96, and 5.62 eV, respectively. The ε spectra are in reasonable agreement with those from theoretical calculations.
通过共蒸发法在熔融石英上沉积了多晶Cu2ZnSnS4薄膜。选择的厚度约为100 nm，以避免因生长的较厚薄膜而导致其光学性能出现伪影。用X射线荧光、拉曼位移光谱、扫描透射电子显微镜和能量色散X射线光谱对薄膜的成分和相进行了检测。采用改进的具有双侧测量几何结构的光谱椭偏测量方法，提取了Cu2ZnSnS4薄膜在0.73至6.5 eV之间的复介电常数ε = ε1 + iε2。分别在1.32（基本带隙）、2.92、3.92、4.96和5.62 eV处观察到五个临界点。ε光谱与理论计算结果合理吻合。
