Thin films of amorphous (a-Si:H) and nanocrystalline (nc-Si:H) hydrogenated silicon are used to form tandem structures for solar cell applications [1]. a-Si:H absorbs light better in short-wavelength region of the solar spectrum, while nc-Si:H is a better absorber for longer-wavelength light. Therefore, the usage of these materials in a tandem leads to the increase of the absorption of sunlight and to the increase of the efficiency. One of the most effective manufacturing methods for nc-Si:H is a laser crystallization of a-Si:H films. In the majority of published works devoted to the laser crystallization of amorphous silicon undoped amorphous silicon is used as a precursor material. At the same time there is almost no data on the properties of the modified by laser radiation doped aSi:H. Therefore, it is of interest to conduct these researches, particularly with the boron doped films. Femtosecond laser irradiation of a-Si:H films with various laser fluences may lead to the formation of materials with essentially different structures and properties. So, the results of researches of electric and photoelectric properties of boron doped a-Si:H films that were irradiated with femtosecond laser pulses with various laser fluences are presented in this work.   a-Si:H films with a thickness of 300 nm were prepared by plasma enhanced chemical vapor deposition from a gas phase during decomposition of monosilane (SiH4) and diborane (B2H6) mix in plasma of the high-frequency glow-discharge. Volume ratio of gases in the reaction chamber was [B2H6]/[SiH4] = 10-4. Yb:KGW laser system with repetition rate of 200 kHz and emission wavelength of 515 nm was used for a-Si:H films processing. Pulse duration was 330 fs. The scanning method of processing was used. Modification of a-Si:H structure was carried out with different laser fluences: 0, 16, 24, 48 and 64 mJ/сm2.   Laser treatment with fluence exceeding 24 mJ/cm2 resulted in the partial crystallization of a-Si:H with formation of nanocrystalline silicon layer on film surface. Modification of films’ structure resulted in 5 orders of magnitude increase of their conductivity value and considerable decrease of activation energy of temperature dependence of dark conductivity. Small value of activation energy of modified films points to the formation of heavily boron doped nanocrystalline silicon that could be explained by the increase of doping efficiency of the films during their crystallization.   This work was supported by the Ministry of Education and Science of the Russian Federation (grant no. 14.604.21.0085, identification number RFMEFI60414X0085).