Temperature dependence of the band gap of Cd1−xZnxTe alloys of low zinc concentrations
Temperature dependence of the band gap of Cd1−xZnxTe alloys of low zinc concentrations
复制标题
低锌浓度 Cd1−xZnxTe 合金带隙的温度依赖性
DOI：
10.1063/1.362374
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
R. Baquero
中科院分区：
文献类型：
--
作者：
F. Sánchez;H. Navarro‐Contreras;G. Ramı́rez;M. Vidal;O. Zelaya;M. E. Rodríguez;R. Baquero
锌浓度在 0 至 0.3 范围内的 Cd1−xZnxTe 合金的基本带隙 E0 的温度依赖性已通过调制光反射 (PR) 确定。室温下，E0 的变化范围为 x=0.00 时的 1.511 eV 至 x=0.3 时的 1.667±0.008 eV；10 K 时，E0 的变化范围为 x=0.00 时的 1.602 eV 至 x=0.3 时的 1.762±0.004 eV。测得的展宽参数 Γ 在室温下的值在 25 至 45 meV 之间，并且随着温度的降低而降低在 10 K 时单调到 5 meV 或更小的值。对于所有研究的样品，众所周知的 Varshni 公式 E(T)=E(0)−AT2/(T+θ) 很好地描述了观察到的带隙能量的温度依赖性。 PR 温度展宽是很好理解的，假设它是由负责 LO 声子带间跃迁 PR 信号的激子电子空穴对的散射引起的。
The temperature dependence of the fundamental band‐gap E0 of Cd1−xZnxTe alloys with zinc concentrations in the 0 to 0.3 range has been determined by modulated photoreflectance (PR). E0 is found to vary from 1.511 eV for x=0.00 to 1.667±0.008 eV for x=0.3, at room temperature and from 1.602 eV at x=0.00 to 1.762±0.004 eV for x=0.3 at 10 K. The measured broadening parameters Γ have values between 25 and 45 meV at room temperature and decrease monotonically to values around 5 meV or smaller at 10 K. The temperature dependence of the observed band gap energies is well described by the well known Varshni formula E(T)=E(0)−AT2/(T+Θ) for all samples studied. The PR temperature broadening is well understood assuming that it results from the scattering of the excitonic electron‐hole pair responsible of the band‐to‐band transition PR signal off LO phonons.