使用太赫兹快速探测器测量硅少数载流子寿命

利用脉冲触发信号在半导体中产生非平衡态载流子的方式，提出一种使用太赫兹连续源和超快速响应探头测量半导体少数载流子寿命的方法，用于表征半导体的瞬态载流子动力学过程。根据上述设计原理及思路，以泵浦光作为周期性激励信号，搭建出一套工作时间窗口为纳秒到秒量级，时间精度在纳秒量级的非接触式半导体少数载流子寿命测量系统，具有装置简单、操作方便、成本低廉等优点。使用搭建的系统对不同掺杂类型、不同掺杂浓度、不同厚度单晶硅的非平衡态少数载流子寿命进行测量。最后，通过改变泵浦光单脉冲能量，对单晶硅光生载流子寿命进行测量，结果表明单晶硅少数载流子寿命随着泵光能量的增大而变长。该系统所实现的宽工作窗口、高时间精度太赫兹快速过程的探测，可应用于太赫兹领域的快速成像和快速生物响应探测。

Measurement of minority carrier lifetime in silicon by high speed terahertz detector

Using pulse trigger signal to generate non-equilibrium carriers in semiconductor, a method for minority carrier lifetime mapping of semiconductor was proposed, with the aid of a terahertz continuous wave source and an ultrafast-response probe, which can apply for characterizing transient carrier dynamics in semiconductor. Based on the above-mentioned design principles, a non-contact minority carrier lifetime measuring system was set up by using the optical pump as the periodic excitation, whose time window was from nanosecond to second and temporal resolution was the order of nanosecond. The system owned various advantages, such as simple device, convenient operation and low cost. The non-equilibrium minority carrier lifetime of monocrystalline silicon with different doping types, different doping concentration, and different thickness were measured by using our system. Finally, the photo-generated carrier lifetime of the monocrystalline silicon was measured through changing the optical pump power. Result shows that the minority carrier lifetime of monocrystalline silicon increases with the enhancement of pump power. The wide-working-window and high-time-resolution detection of terahertz fast processes, which is realized by the proposed system, can be applied for the fast imaging and rapid bio-response detection at the terahertz range.