Luminescent properties of nitrogen doped gap semiconductor studied with photothermal deflection spectroscopy

摘要

Abstract: Theoretical analysis of the relation between amplitude of photothermal signals in nonuniform samples and modulating frequency used photothermal deflection spectroscopy (PDS) shows: compared with the curve of logarithmic amplitude of PDS signals of uniform substrate materials, the curve inclination of logarithmic amplitude via frequency omega increases when absorptive index of p-layer is smaller than that of n-layer in nonuniform Gap:N, otherwise, it decreases. By comparing this result with experimental results, we can obtain concentration distribution of nitrogen in p-layer and n-layer of Gap:N. Meanwhile, absorption spectra under different modulating frequencies at room temperature have been measured, and the possibility of measurement of optical and thermal characteristics at different depth of nonuniform samples under various modulating frequencies is indicated. In a word, this paper suggests a method to measure internal characteristics of nonuniform materials without damage, which has been verified in experiment. !6