Title : An AlGaAs/GaAs quantum resonant-tunneling based model thermometer
Abstract:
In this presentation, we propose a model thermometer based on resonant carrier transport in an AlGaAs/GaAs double-barrier heterostructure. We use a one-dimensional model to describe the effective potential of the heterostructure, which consists of two quantum barriers (AlGaAs layers) separated by a quantum well (GaAs layer). We consider the temperature dependence not only of the conduction band offset between the GaAs and AlGaAs layers, but of the effective mass of the carriers as well. The heterostructure is connected on both sides to two heavily doped GaAs layers, referred to as the emitter and the collector, where the carriers exist. When an external bias is applied between the emitter and the collector, the resonant tunneling mechanism is activated. This causes the disturbed energy levels of the quantum well quasi-states to align with the Fermi level of the emitter, enhancing resonant tunneling. The complex energy disturbance of the quasi-states reveals both the real energy shift and the width of the resonance, with the latter providing the resonant transport time. By employing quasi-classical path integral theory, we can analytically derive the Green’s function of the heterostructure and calculate the resonance positions. These positions depend on various parameters, such as the geometry of the heterostructure, the applied bias, the aluminum mole fraction, and temperature. We calculate the resonant transport time as a function of the existing temperature. By inverting this relationship, we can obtain an accurate measurement of the heterostructure's temperature based on the resulting resonant time. Our results provide concise analytical relationships involving parameters such as barrier and well thickness, as well as shape, enabling the prediction and optimization of the performance of various nanoscale devices and particularly aiding in determining the required temperature for effective sensor function.
Audience Take Away Notes:
- Someone can actually apply the method described above, to construct an accurate and realistic thermometer based on a AlxGa1-xAs/GaAs nanostructures to measure temperature with high accuracy
- As mentioned in the abstract, this work connects the structural and material properties of the AlxGa1-xAs/GaAs heheterostructure to the ambient temperature. Thus, our results provide concise analytical relationships involving parameters such as barrier and well thickness, as well as shape, enabling the prediction and optimization of the performance of various nanoscale devices and particularly aiding in determining the required temperature for effective sensor function. In addition someone can learn about path integrals and think about expanding his teaching in Chemistry calculations by incorporating the method
- Since the findings of the current work come in analytic form, a designer may vary Aluminum’s heterostructure parameters to reach the desired temperature measure with higher accuracy
- New information: Temperature measure can be improved by exploiting both macroscopic and microscopic properties of Aluminum’s heterostructure
