Fabrication of terahertz detectors based on InAs/AISb/AlGaSb/GaSb heterostructures

描述了探测太赫兹波的Sb基二极管的制备和特性。采用分子束外延技术在半绝缘的GaSb衬底上生长了InAs/AlSb/AlGaSb/GaSb异质结。目的是为了合理设计二极管结构，以提高γ在低电压下的I-V特性的灵敏度、曲率。我们改变了Al_xGa_1-x&Gt；Sb的Al组分x和AlSb势垒的厚度y。当x=0.25，y=1.5 nm时，得到了最大曲率y=16.9^&lt；-1&gt；，并报道了InAs/AlGaSb三端结构的电子输运性质。由于电子的弹道性质，该结构在4.2K-300K之间表现出非线性电子输运性质。当以推挽方式向左右支路施加直流输入电压(V_L和V_R)时，中心支路V_C处的电压在4.2K-300K范围内相对于V_L表现出明显的整流特性。此外，在中心支路接地和输入电压采用推挽方式的情况下，观察到了流经中心支路的电流的整流效果。这些明显的非线性效应表明，InAs/AlGaSb三端器件是利用弹道电子输运特性的未来有吸引力的应用之一。

Fabrication and characterization of Sb-based diodes for the detecting terahertz waves are described. InAs/AISb/AIGaSb/GaSb heterostructures were grown on a semi-insulating GaAs substrate by molecular beam epitaxy. The purpose is to properly design the diode structure in order to improve the sensitivity, the curvature γ in the I-V characteristics at low voltages. We changed the Al composition, x of the Al_xGa_<1-x>Sb and thickness, y of the AlSb barrier. The maximum curvature y of 16.9^<-1> was obtained for the x=0.25 and the y=1.5nm.Electron transport properties in InAs/AlGaSb three-terminal structures are also reported. This structure exhibited nonlinear electron transport properties from 4.2K to 300K because of ballistic properties of electrons. When dc input voltages are applied to the left and right branches in the push-pull fashion (V_L and V_R), the voltage measured at the central branch V_C showed obvious rectification properties with respect to V_L from 4.2K to 300K. In addition, current rectification effects in the current flow through the central branch were observed with the central branch being grounded and input voltages in push-pull fashion. These clear nonlinear effects indicate that the InAs/AlGaSb three-terminal device is one of the attractive future applications utilizing ballistic electron transport properties.