Differential photoreflectance from a high‐mobility and highly luminescent two‐dimensional electron gas
Differential photoreflectance from a high‐mobility and highly luminescent two‐dimensional electron gas
复制标题
高迁移率和高发光二维电子气的差分光反射
DOI：
10.1063/1.349427
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发表时间：
1991
影响因子：
3.2
通讯作者：
A. Badakhshan
中科院分区：
文献类型：
--
作者：
M. Sydor;A. Badakhshan
我们提出了一种差分调制技术，该技术可以有效地提取具有超室温光致发光的−/Al_xGa_1_xAs样品的光反射率。利用这一技术，我们从高电子迁移率晶体管的三角势垒区获得了光反射率。令人惊讶的是，来自势垒的信号可以从两层重掺杂材料的下面提取出来，这使得差示光反射在检测高电子迁移率晶体管中的二维电子气时很有用，这些晶体管覆盖着掺杂的保护性GaAs帽，通常会消除掩埋界面上的PR。我们分离了1.447 eV和1.472 eV处的类吸收光反射峰，表明它们的能量和幅度之比符合非对称三角势垒的二维格理论。
We present a differential modulation technique which is effective in extracting the photoreflectance from GaAs/AlxGa1−xAs samples exhibiting excessive room‐temperature photoluminescence. Using the technique, we obtain the photoreflectance from the triangular potential‐well region of a high‐electron‐mobility transistor. Surprisingly, the signal from the potential well can be extracted from underneath two layers of heavily doped material, making differential photoreflectance useful in detection of two‐dimensional electron gas in high‐electron‐mobility transistors cladded with doped protective GaAs caps which usually obliterate the PR from the buried interfaces. We isolate absorptionlike photoreflectance peaks at 1.447 and 1.472 eV and show that their energies and the ratio of their amplitudes agree with the 2DEG theory for asymmetric triangular potential well.