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

描述了用于探测太赫兹波的sb基二极管的制造和特性。采用分子束外延的方法在半绝缘GaAs衬底上生长出InAs/AISb/AIGaSb/GaSb异质结构。目的是合理设计二极管结构，以提高灵敏度，曲率γ在低电压下的I-V特性。我们改变了Al_xGa_<1-x >sb的Al组分x和AlSb势垒的厚度y。当x=0.25和y=1.5nm时，最大曲率y为16.9^<-1>。还报道了InAs/AlGaSb三端结构中的电子输运性质。由于电子的弹道性质，该结构在4.2K ~ 300K范围内表现出非线性的电子输运性质。当直流输入电压以推挽方式（V_L和V_R）分别施加到左支路和右支路时，在中心支路V_C处测得的电压相对于V_L在4.2K到300K范围内表现出明显的整流特性。此外，在中心支路接地且输入电压为推挽方式的情况下，观察到通过中心支路的电流的电流整流效应。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有吸引力的未来应用之一。

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.