二维半导体的相干声学声子研究进展OA北大核心CSTPCD

The coherent acoustic phonons generated by femtosecond laser pulse excitation of thin-film materials can obtain non-destructive interface structure characteristics of light-emitting materials and devices.It is important for non-destructive testing and imaging of functional interfaces of opto-electronic devices.Compared with traditional metal thin-film photoacoustic transducers with thermoelastic mechanisms,two-dimensional semiconductor films own the advantag-es of broad spectrum absorption,atomic-level surface flatness,and robust control of the layer number.During the inter-action of femtosecond laser pulse and two-dimensional semiconductor,coherent acoustic phonon oscillation can be gen-erated,which set a foundation for further launching ultrafast acoustic pulses to extract interface information.This should be widely applicable for nondestructive evaluation of defect distribution,mechanical properties,and interface quality of light-emitting devices.In this paper,we introduce the research progress of coherent acoustic phonons in two-dimension-al semiconductors and overlook the scientific significance of ultrafast opto-acoustic measurement technique.