信息安全是国家重大战略需求，量子通信是目前唯一被严格证明无条件安全的通信方式，然而其中高性能单光子APD器件的缺失已成为阻碍我国量子通信发展的瓶颈。为此，本项目将融合Si与Ge各自优势，研制高性能Ge/Si吸收区与倍增区分离结构单光子APD器件。课题将研究Ge/Si APD单光子探测器暗计数的来源以及载流子与杂质和缺陷作用的动力学过程，阐明器件暗计数和后脉冲效应的抑制途径；研究硅衬底上锗材料外延生长，揭示大失配异质外延应力弛豫及位错迁移与抑制机制，获得低位错密度Ge/Si APD异质材料的制备方法；研究Ge/Si APD器件表面钝化等关键工艺，掌握高性能Ge/Si APD器件制备技术；建立器件性能测试分析平台，掌握单光子APD器件性能评估方法；研制出暗记数率低至10kcps、探测率高于15%、工作频率达5GHz的高性能Ge/Si单光子APD器件。

The national major strategic requires information security, at present only quantum communications method is proved to absolute safe. However, the lack of high-performance Single-Photon Avalanche Diode Detectors (SPADs) has become a development-hampering bottleneck. Thus, our project aims to develop high-performance Ge/Si SPAD device with separate absorption region and multiplication region structure. Our research includes the following contents: (1) the origin of SAPD dark count rates (DCRs), dynamics of interactions between carriers, impurities, and defects and exploring the inhibition pathway of DCRs and afterpulsing effect; (2) Ge epitaxy growth on Si substrate, revealing the mechanics of hetero-epitaxy stress relaxation and dislocation migration and fabricating Ge/Si APD hetero-structure with low dislocation density; (3) exploring the key techniques of Ge/Si APD device (passivation technique) to fabricate high-performance Ge/Si APD device; (4) building the performance test analysis platform and mastering evaluation methods of Ge/Si SPAPD device. (5) fabricating high-performance Ge/Si SPAPD device with low DCRs (<10kcps), high detecting rates (>15%) and 5 GHz frequency.