High temperature optical absorption edge of CdTe single crystal
High temperature optical absorption edge of CdTe single crystal
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DOI：
10.1063/1.4895494
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发表时间：
2014-09-14
影响因子：
3.2
通讯作者：
Bugar, M.
中科院分区：
文献类型：
--
作者：
Belas, E.;Uxa, S.;Bugar, M.
在295 ~ 1223 K的饱和Cd压力下，用红外透射法测量了大块CdTe单晶的光学吸收边。直接测定吸收系数至100 cm（-1）。对于较高的值，根据乌尔巴赫指数规则通过外推光谱来估计。我们观察到，在CdTe中不存在常见的与温度无关的外推乌尔巴赫吸收边相交，即“乌尔巴赫焦点”。建立了E-g(300 K) = 1.518 eV和dE(g)/dT = - 4.4 x 10(-4) eV/K定义的带隙能量E-g的温度依赖关系，通过拟合带边温度依赖吸收系数α (g)(T) = 6600 - 4T (K) (cm(-1))，假设E-g与温度呈线性关系。(C) 2014 AIP出版有限责任公司
The optical absorption edge of bulk CdTe single crystal was measured by infrared transmission under saturated Cd pressure in the temperature interval 295-1223 K. The absorption coefficient was directly determined up to the value of 100 cm(-1). For higher values, it was estimated by extrapolating the spectra according to the Urbach exponential rule. It was observed that the common temperature-independent intersection of extrapolated Urbach absorption edge, the "Urbach focus," does not exist in CdTe. The temperature dependence of band-gap energy E-g defined by E-g(300 K) = 1.518 eV and dE(g)/dT = - 4.4 x 10(-4) eV/K was established, postulating linear temperature dependence of E-g by fitting the temperature dependent absorption coefficient at the band edge alpha(g)(T) = 6600 - 4T (K) (cm(-1)). (C) 2014 AIP Publishing LLC.