Schnedermann Christoph, Sung Jooyoung, Pandya Raj, Verma Sachin Dev, Chen Richard Y S, Gauriot Nicolas, Bretscher Hope M, Kukura Philipp, Rao Akshay
Department of Physics, Cavendish Laboratory , University of Cambridge , JJ Thompson Avenue , Cambridge CB3 0HE , United Kingdom.
Physical and Theoretical Chemistry Laboratory , University of Oxford , South Parks Road , Oxford OX1 3QZ , United Kingdom.
J Phys Chem Lett. 2019 Nov 7;10(21):6727-6733. doi: 10.1021/acs.jpclett.9b02437. Epub 2019 Oct 17.
We present a novel optical transient absorption and reflection microscope based on a diffraction-limited pump pulse in combination with a wide-field probe pulse, for the spatiotemporal investigation of ultrafast population transport in thin films. The microscope achieves a temporal resolution down to 12 fs and simultaneously provides sub-10 nm spatial accuracy. We demonstrate the capabilities of the microscope by revealing an ultrafast excited-state exciton population transport of up to 32 nm in a thin film of pentacene and by tracking the carrier motion in p-doped silicon. The use of few-cycle optical excitation pulses enables impulsive stimulated Raman microspectroscopy, which is used for in situ verification of the chemical identity in the 100-2000 cm spectral window. Our methodology bridges the gap between optical microscopy and spectroscopy, allowing for the study of ultrafast transport properties down to the nanometer length scale.
我们展示了一种新型的光学瞬态吸收和反射显微镜，它基于衍射极限泵浦脉冲与宽场探测脉冲相结合，用于对薄膜中超快载流子输运进行时空研究。该显微镜实现了低至12飞秒的时间分辨率，并同时提供低于10纳米的空间精度。我们通过揭示并五苯薄膜中高达32纳米的超快激发态激子载流子输运以及跟踪p型掺杂硅中的载流子运动，展示了该显微镜的能力。使用少周期光激发脉冲能够实现脉冲受激拉曼显微光谱，用于在100 - 2000厘米光谱窗口内对化学特性进行原位验证。我们的方法弥合了光学显微镜和光谱学之间的差距，允许对低至纳米长度尺度的超快输运特性进行研究。
