量子点场效应单光子探测器二维电子气载流子浓度研究

Two-dimensional electron gas carrier concentration analysis of the quantum dots field effect single photon detector

设计了一种基于场效应晶体管的量子点场效应单光子探测器(quantum dot field effect transistor,QDFET),建立了二维电子气(two-dimensional electron gas,2DEG)的薛定谔方程和泊松方程,通过对薛定谔方程和泊松方程的自洽求解,对2DEG的载流子浓度进行了模拟。模拟结果显示,AlGaAs的Al组分、δ掺杂层的掺杂浓度以及隔离层的厚度对于2DEG的载流子浓度均有影响。为了使2DEG具有较高的载流子浓度,AlGaAs的Al组分应为0.2~0.4,δ掺杂浓度应为6~8×10^(13)/cm^2,隔离层厚度应在50nm以下。通过对2DEG的载流子浓度进行研究,可以掌握2DEG载流子浓度的影响因素,从而通过优化QDFET结构,可提高2DEG的载流子浓度。这对于高灵敏度QDFET的制备具有重要的意义和应用价值。

A quantum dot field effect transistor （QDFET） is designed. The carrier concentration is simulated by building and self-consistently solving the Schrodinger equation and Poisson equation of the QDFET. The simulation results show that the carrier concentration of the 2DEG is affected by the A1 component of the A1GaAs layer, doping con- centration of the δ doping layer, and the thickness of the spacer layer. To achieve higher carrier concentration within the 2DEG, the A1 component of the A1GaAs layer should be 0. 2-0. 4, the doping concentration of the - doping layer should be 6-8×10^13/cm^2 , and the thickness of the spacer layer should be below 50 nm. The effecting factors of the carrier con- centration of 2DEG are got, so that the structure of QDFET can be optimized to promote the carrier concentration of 2DEG, which has great significance and application values for fabrication of highly sensitive QDFET.