Optical properties and structure of tellurium–germanium– bismuth–antimony compounds with fast phase-change capability
Optical properties and structure of tellurium–germanium– bismuth–antimony compounds with fast phase-change capability
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具有快速相变能力的碲锗铋锑化合物的光学性质和结构
DOI：
10.1063/1.1348327
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发表时间：
2001
影响因子：
3.2
通讯作者：
E. Y. Huang
中科院分区：
文献类型：
--
作者：
C. Lee;T. Chin;E. Y. Huang
通过射频溅射在 Si (100) 或聚碳酸酯基板上制备厚度为 100 nm 的四元 TeGeBiSb 非晶薄膜。随后在300℃下退火10分钟获得结晶薄膜。通过 X 射线衍射法在四元系中鉴定出至少两个具有六方和菱面体结构的相。它们的组成接近分子式Te5Ge4Bi4Sb和Te5Ge4Bi7Sb，c/a比分别为5.5和9.4。 Te5Ge4Bi4Sb薄膜在整个可见光谱范围内表现出20%~25%的合理反射率对比度，而Te5Ge4Bi7Sb薄膜的反射率对比度随着波长的减小呈现急剧降低的趋势，并在波长小于470 nm处变为负值。热分析结果表明，薄膜在236-266℃左右结晶，相应的活化能为2.67-2.88 eV。反射率对比度的变化是根据具有 Bi 含量的 TeGeBiSb 材料的光学带隙的变化来解释的。
Quaternary TeGeBiSb amorphous films, 100 nm in thickness, were prepared by rf sputtering onto either a Si (100) or polycarbonate substrate. Crystalline films were obtained by subsequent annealing at 300 °C for 10 min. At least two phases with hexagonal and rhombohedral structures were identified by x-ray diffractometry in the quaternary system. Their compositions are close to formulas Te5Ge4Bi4Sb and Te5Ge4Bi7Sb, with c/a ratios of 5.5 and 9.4, respectively. The Te5Ge4Bi4Sb film shows a reasonable reflectivity contrast ranging from 20% to 25% in the whole visible spectrum, while the reflectivity contrast of Te5Ge4Bi7Sb film shows a sharp lowering tendency with decreasing wavelength and turns negative at wavelengths smaller than 470 nm. Results of thermal analyses show that the films crystallize at around 236–266 °C with corresponding activation energies 2.67–2.88 eV. The change in reflectivity contrast is explained based on the variation in optical band gaps of the TeGeBiSb materials with either Bi conten...