以共振隧穿结构为压阻器件可以得到较高的灵敏度,但是当实验选择不同的工作偏压时,这种压阻效应表现得极其不同。由于高灵敏度是依靠较高的I-V曲线斜率获得的,因此最初人们希望选择具有较高峰谷比结构作为器件。但是有些区域的斜率过大,以至于压阻效应失去线性及稳定性而变得没有实用价值。另外,在某些工作区域由于共振隧穿结构本身具有的双稳态特性,而使其完全失去压阻特性。本文对这些问题进行了系统分析,并对一个具体的结构,分析其工作区域及特性,给出最高灵敏度可达700左右。
A higher sensitivity can be achieved by making use of resonant tunneling structures as a piezoresistance device, but it will be very different from each other when different bias position is chosen. At first, a structure with high peak -to -valley ratio was used as the device because the sensitivity depends on the slop of I - V curves. But it will be useless when the stability and lineariry has lost in the case that slop becomes too big. Another aspect that has to be considered is the intrinsic bistability of the resonant tunneling structure in the negative differential resistance region, where the piezoresistance effect become senseless. This paper has studied all these problems systematically, and calculated a sample which gives a sensitivity as high as 700, but the effective range has to be restricted in a narrow region.