Photoacoustic frequency heat‐transmission technique is used to study thermal and carrier transport properties in low‐doped silicon wafers. Amplitude and phase photoacoustic signals as a function of modulation frequency of incident optical beam are measured using different experimental conditions. The thermal diffusivity, coefficient of excess carrier diffusion, carrier lifetime, and the surface recombination velocity were determined by comparing experimental results and calculated theoretical photoacoustic signals. The suitability of the photoacoustic frequency heat‐transmission technique as a contactless diagnostic method is assessed in comparison with the more conventional photothermal deflection and photothermal modulated reflection techniques. ©1995 American Institute of Physics.