Method for determining the carrier lifetime

A method determines the carrier lifetime in a point of a surface of a sample, and includes in absence of illumination, measuring, at the point, a parameter P via atomic force microscopy technique (AFM) to obtain a value Pdark. The point is illuminated with a continuous light beam and the parameter P is measured, at the point, via AFM to obtain a value Psat. The point is successively illuminated with continuous modulated light beams each having a different frequency ft that varies between a minimum frequency fmin and a maximum frequency fmax, with the modulated light beams having a duty cycle D. For each modulated light beam, the parameter P is measured, at the point, via AFM in such a way as to obtain a value Ptransi for each frequency fi. The carrier lifetime is calculated on point with the values of Psat, Pdark, the duty cycle D, and fmax.