Terahertz photoconductance dynamics of semiconductors from sub-nanosecond to millisecond timescales
Terahertz photoconductance dynamics of semiconductors from sub-nanosecond to millisecond timescales
复制标题
DOI：
10.1063/5.0130721
复制
发表时间：
2023-01
影响因子：
4
通讯作者：
E. Butler-Caddle;N. Grant;S. Pain;J. Murphy;K. Jayawardena;J. Lloyd‐Hughes
中科院分区：
文献类型：
--
作者：
E. Butler-Caddle;N. Grant;S. Pain;J. Murphy;K. Jayawardena;J. Lloyd‐Hughes
光泵浦太赫兹探测光谱（OPTP）是一种多用途的非接触测量技术，可以测量瞬态光电导衰减，时间分辨率为飞秒。然而，它的最大时间范围仅限于几纳秒的机械延迟线使用。我们将OPTP的时间范围扩展到毫秒或更长，同时保留亚纳秒分辨率。一个单独的泵浦激光器与探测脉冲电同步，允许用电子延迟发生器控制泵浦-探测延迟。我们通过检查寿命超过六个数量级的半导体的光电导衰减来证明这种技术的能力：III-V，金属卤化物钙钛矿，锗和硅。直接比较硅从OPTP和电感耦合光电导衰减的结果突出了更高的空间和时间分辨率的OPTP，这使得在平面内和平面外的载流子扩散进行研究。
Optical pump terahertz probe spectroscopy (OPTP) is a versatile non-contact technique that measures transient photoconductance decays with femtosecond temporal resolution. However, its maximum temporal range is limited to only a few nanoseconds by the mechanical delay lines used. We extended the temporal range of OPTP to milliseconds and longer while retaining sub-nanosecond resolution. A separate pump laser was electrically synchronized to the probe pulses, allowing the pump–probe delay to be controlled with an electronic delay generator. We demonstrated the capabilities of this technique by examining the photoconductance decays of semiconductors with lifetimes ranging over six orders of magnitude: III-Vs, metal halide perovskites, germanium, and silicon. A direct comparison of results on silicon from OPTP and inductively coupled photoconductance decay highlighted the higher spatial and temporal resolution of OPTP, which allowed in-plane and out-of-plane carrier diffusion to be studied.