A resonant cavity-enhanced （RCE） quantum dot （QD） field-effect transistor （RCEQDFET） is designed for single- photon detection in this paper. Adding distributed Bragg reflection （DBR） mirrors to the single-photon detector （SPD）, we improve the light absorption efficiency of the SPD. The effects of the reflectivity of the mirrors, the thickness and light absorption coefficient of the absorbing layer on the detector＇s light absorption efficiency are investigated, and the resonant cavity is determined by using the air/semiconductor interface as the mirror on the top. Through analyzing the relationship between the refractive index of AlxGal_xAs and A1 component, we choose A1As/Alo.15Gao.85As as the material of the mirror on the bottom. The pairs of A1As/Alo.15Gao.85As film are further determined to be 21 by calculating the reflectivity of the mirror. The detector is fabricated from semiconductor heterostructures grown by molecular beam epitaxy. The reflection spectrum, photoluminescence （PL） spectrum, photocurrent response, and channel current of the detector are tested and the results show that the RCEQDFET-SPD designed in this paper has better performances in photonic response and wavelength selection.
采用分子束外延技术对δ掺杂GaAs/AlxGa1 xAs二维电子气(2DEG)样品进行了生长.在样品生长过程中,分别改变掺杂浓度(Nd)、空间隔离层厚度(Wd)和AlxGa1 xAs中Al组分(xAl)的大小,并在双温(300 K,78 K)条件下对生长的样品进行了霍尔测量;结合测试结果,分别对Nd,Wd及xAl与GaAs/AlxGa1 xAs 2DEG的载流子浓度和迁移率之间的关系规律进行了细致的分析讨论.生长了包含有低密度InAs量子点层的δ掺杂GaAs/AlxGa1 xAs2DEG样品,采用梯度生长法得到了不同密度的InAs量子点.霍尔测量结果表明,随着InAs量子点密度的增加,GaAs/AlxGa1 xAs 2DEG的迁移率大幅度减小,实验中获得了密度最低为16×108/cm2的InAs量子点样品.实验结果为内嵌InAs量子点的δ掺杂GaAs/AlxGa1 xAs 2DEG的研究和应用提供了依据和参考.
