图 1  (a)两种厚度Sb₂Se₃薄膜在760和860 nm处$ {{\Delta }{R}}/{{R}} $归一化曲线比较; (b) Sb₂Se₃/空气界面$ \dfrac{\partial{R}}{{\partial n}} $和$ \dfrac{\partial{R}}{{\partial k}} $曲线; (c) Sb₂Se₃/空气界面$ {{\Delta }{R}}/{{R}} $随温度的变化, 其中R为300 K时的界面反射率, $ {\Delta }{R} $为相对300 K条件下界面反射率的变化

Fig. 1.  (a) Comparisons of $ {{\Delta }{R}}/{{R}} $ curves at probe wavelengths of 760 and 860 nm from Sb₂Se₃ film of two thicknesses, where the $ {{\Delta }{R}}/{{R}} $ curves have been normalized; (b) $ \dfrac{\partial{R}}{{\partial n}} $ and $ \dfrac{\partial{R}}{{\partial k}} $ curves of Sb₂Se₃/air interface; (c) dependence of $ {{\Delta }{R}}/{{R}} $ at Sb₂Se₃/air interface on temperature, where R is the reflectivity of the interface at 300 K, and $ {\Delta }{R} $ is the reflectivity difference with respect to R of the interface at 300 K.

图 2  Sb₂Se₃薄膜载流子弛豫过程示意图

Fig. 2.  Schematic diagram of carrier relaxation in Sb₂Se₃ film.

图 3  (a) Sb₂Se₃与Sb₂Se₃/CdS薄膜的吸收光谱; (b) Sb₂Se₃与Sb₂Se₃/CdS薄膜的XRD图谱; (c) Sb₂Se₃薄膜的表面形貌; (d) Sb₂Se₃薄膜的截面形貌

Fig. 3.  (a) Absorbance spectra of Sb₂Se₃ and Sb₂Se₃/CdS film; (b) XRD diffraction spectra of Sb₂Se₃ and Sb₂Se₃/CdS film; (c) surface morphologies of Sb₂Se₃ film; (d) cross-sectional morphology of Sb₂Se₃ film.

图 4  (a) Sb₂Se₃薄膜的相对反射率变化$ {{\Delta }{R}}/{{R}} $的二维图像(激发波长550 nm, 载流子浓度1.55 × 10²⁰cm^–3); (b)典型时间延迟对应的$ {{\Delta }{R}}/{{R}} $谱; (c)典型探测波长对应的$ {{\Delta }{R}}/{{R}} $动力学曲线

Fig. 4.  (a) Two-dimensional image of relative reflectivity change $ {{\Delta }{R}}/{{R}} $ of Sb₂Se₃ film excited by 550 nm laser (300 nJ); (b) $ {{\Delta }{R}}/{{R}} $ with various probe wavelengths at three typical time delays; (c) evolutions of $ {{\Delta }{R}}/{{R}} $ of four typical probe wavelengths

图 5  (a)不同激发光子能量条件下860 nm探测波长处$ {{\Delta }{R}}/{{R}} $动力学曲线比较; (b)不同激发光子能量条件下载流子热化和带隙收缩时间; (c)不同载流子浓度条件下860 nm探测波长处$ {{\Delta }{R}}/{{R}} $动力学曲线比较(激发波长550 nm); (d)不同载流子浓度条件下载流子热化和带隙收缩时间

Fig. 5.  (a) Comparisons of kinetic curves of $ {{\Delta }{R}}/{{R}} $ at probe wavelength 860 nm with different excitation photon energies; (b) carrier thermalization and band gap renormalization times with different excitation photon energies; (c) comparisons of kinetic curves of $ {{\Delta }{R}}/{{R}} $ with different carrier concentrations (excitation wavelength of 550 nm); (d) carrier thermalization and band gap renormalization time with different carrier concentrations.

图 6  (a)不同激发光子能量条件下探测波长760 nm处${{\Delta }{R}}/{{R}}$的动力学过程II比较; (b)不同激发光子能量条件下${{\Delta }{R}}/{{R}}$的动力学过程II的衰减寿命

Fig. 6.  (a) Comparisons of kinetics II of ${{\Delta }{R}}/{{R}}$ at 760 nm with different excitation photon energies; (b) decay lifetime of kinetics II of ${{\Delta }{R}}/{{R}}$ with different excitation energies.

图 7  (a)典型时间延迟条件下Sb₂Se₃/CdS的相对反射率变化$ {{\Delta }{R}}/{{R}} $谱(激发波长650 nm); (b) Sb₂Se₃和Sb₂Se₃/CdS在495 nm处${{\Delta }{R}}/{{R}}$动力学曲线对比

Fig. 7.  (a) Relative reflectance change $ {{\Delta }{R}}/{{R}} $ spectra of Sb₂Se₃/CdS at three time delays (excitation wavelength of 650 nm); (b) comparison of kinetic curves of $ {{\Delta }{R}}/{{R}} $ at 495 nm for Sb₂Se₃ and Sb₂Se₃/CdS.

图 8  4种载流子浓度条件下Sb₂Se₃与Sb₂Se₃/CdS在760 nm处的$ {{\Delta }{R}}/{{R}} $的动力学曲线对比　(a) $ 4.79\times {10}^{19} $ cm^–3; (b) 9.59 × 10¹⁹ cm^–3; (c) 1.44 × 10²⁰ cm^–3; (d) 1.92 × 10²⁰ cm^–3

Fig. 8.  Comparisons of kinetics of $ {{\Delta }{R}}/{{R}} $ at 760 nm for Sb₂Se₃ and Sb₂Se₃/CdS under four different carrier concentrations of (a) $ 4.79\times {10}^{19} $ cm^–3, (b) 9.59 × 10¹⁹ cm^–3, (c) 1.44 × 10²⁰ cm^–3, (d) 1.92 × 10²⁰ cm^–3

图 9  Sb₂Se₃/CdS界面处的主要载流子过程(CB, 导带; VB, 价带)

Fig. 9.  Main carrier processes at the interface of Sb₂Se₃/CdS (CB, conduction band; VB, valence band).