| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a measuring method of any defect in a solid being which finds the size of any lattice defect existent in a trace quantity in a solid such as semiconductor crystals and semiconductor nanocrystals, images a lattice defect distribution, and is applicable to the estimation of electric conductance characteristics for defining the optical response performance of a device. <P>SOLUTION: The relaxation times of coherent phonons or optical excitation carriers excited by a pump&probe spectroscopic method using a femtosecond pulsed laser are measured, and the size of the lattice defect is estimated using the formula:τ=1/Ntσv<SB>th</SB>(τ:relaxation time of coherent phonon (optical excitation carrier), N<SB>t</SB>: defect density,σ: scattering cross section, and v<SB>th</SB>: rate of thermal diffusion). Further, use is made of a microscope objective lens as a condenser for focusing pumping light and probe light onto a solid sample. Hereby, a reflectivity change is measured while scanning the solid sample with an X-Y stage two-dimensionally to plot two-dimensionally the oscillation amplitude or signal intensity of a change in the reflectance or the relaxation time of the coherent phonons or the optical excitation carriers. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
