The transient absorption (TA) experiment allows quantitative characterization of time-dependent absorption of an optically excited sample. Two light pulses are required: femtosecond narrow-bandwidth pump pulse to excite the sample and delayed broad-bandwidth probe pulse to measure the changes in sample transmittance. The resulting difference absorption signal is measured as a function of the probe wavelength and the temporal delay between the pump and probe pulses.

The TA spectrum is much more elaborate than, e.g., a steady-state absorption or fluorescence decay spectrum. It provides information not only on the excited states of the system but also on all the intermediate evolutionary transients and non-emissive states both on the ground and the excited states.

HARPIA-TA can be equipped with a microscopy module HARPIA-MM, enabling spatially-resolved pump-probe measurements with a spatial resolution down to 5 μm. The HARPIA-MM module features a brightfield mode to observe the sample and determine the pump-probe spot location and transmission and reflection modes to carry out the pump-probe measurements.

  • 最低至 2 μm 空间分辨率
  • 可选配宽带宽和单色探测光
  • 电控 XYZ 轴样品台
  • 透射、镜面反射、漫反射几何光学设置
  • 行业领先的灵敏度
  • 330 nm – 24 µm 光谱范围
  • 探测光延迟范围 2 ns – 8 ns
  • 泵浦能量低至nJ级别
  • 低温恒温器和蠕动泵支架
  • 100 fs – 20 ps 连续可调脉宽
  • 最大单脉冲能量 4 mJ
  • 最高输出功率 20 W
  • 单脉冲 – 1 MHz 重复频率
  • BiBurst 脉冲串功能
  • 自动谐波发生器(高达 5 次谐波)
  • 190 fs – 20 ps 连续可调脉宽
  • 最大单脉冲能量 2 mJ
  • 最大输出功率 80 W
  • 单脉冲 – 2 MHz 重复频率
  • 脉冲选择器功能,可按需输出脉冲
  • BiBurst 脉冲串模式
  • 风冷型号

Carrier Transport Across a CdSxSe1–x Lateral Heterojunction Visualized by Ultrafast Microscopy

D. D. Blach, W. Zheng, H. Liu, A. Pan, and L. Huang, The Journal of Physical Chemistry C 21 (124), 11325-11332 (2020).

Femtosecond Transient Absorption Microscopy of Singlet Exciton Motion in Side-Chain Engineered Perylene-Diimide Thin Films

R. Pandya, R. Y. S. Chen, Q. Gu, J. Gorman, F. Auras, J. Sung, R. Friend, P. Kukura, C. Schnedermann, and A. Rao, The Journal of Physical Chemistry A 13 (124), 2721-2730 (2020).

Compressive imaging of transient absorption dynamics on the femtosecond timescale

O. Denk, K. Zheng, D. Zigmantas, and K. Žídek, Optics Express 7 (27), 10234 (2019).

Long-range ballistic propagation of carriers in methylammonium lead iodide perovskite thin films

J. Sung, C. Schnedermann, L. Ni, A. Sadhanala, R. Y. S. Chen, C. Cho, L. Priest, J. M. Lim, H. Kim, B. Monserrat et al., Nature Physics 2 (16), 171-176 (2019).

Ultrafast Tracking of Exciton and Charge Carrier Transport in Optoelectronic Materials on the Nanometer Scale

C. Schnedermann, J. Sung, R. Pandya, S. D. Verma, R. Y. S. Chen, N. Gauriot, H. M. Bretscher, P. Kukura, and A. Rao, The Journal of Physical Chemistry Letters 21 (10), 6727-6733 (2019).

Spatially segregated free-carrier and exciton populations in individual lead halide perovskite grains

S. Nah, B. Spokoyny, C. Stoumpos, C. M. M. Soe, M. Kanatzidis, and E. Harel, Nature Photonics 5 (11), 285-288 (2017).

Two Birds with One Stone: Tailoring Singlet Fission for Both Triplet Yield and Exciton Diffusion Length

T. Zhu, Y. Wan, Z. Guo, J. Johnson, and L. Huang, Advanced Materials 34 (28), 7539-7547 (2016).