Boron-doped and phosphorus-doped thin films ( nc-Si : H) were deposited by RF-PECVD system and applied to fabricate analogue tandem solar cells. The optical performance and morphology of the thin film sample were analyzed. The results showed that the optical band gap, conductivity, hall mobility and carrier concentration of P-type nc-Si : H thin films were 2 . 189 eV, 8 . 01 S / cm, 0 . 521 cm²/ ( V·S) and 9 . 61 X10¹⁹/ cm³, respectively and those of N-type nc-Si : H thin films were 1 . 994 eV,1 . 93 S / cm, 1 . 694 cm²/ ( V·S) and 7 . 113 X10¹⁸/ cm³, respectively. Nanocrystalline grain size was approximate 3 ~5 nm and crystal volume fraction was within 35 % ~ 45 % . The grain deposition was density and it had more uniform size. The analogue tandem solar cells with the structure of Al / AZO / p-nc-Si : H / i-nc-Si : H / n-nc-Si : H / p-nc-Si : H / i-nc-Si : H / n-c-Si / Al were prepared in an area of 20 mmX20 mm and achieved the maximum open-circuit voltage V_OC, short-circuit current I_SC and fill factor of 544 . 3 mV, 85 . 6 mA and 65 . 7 % , respectively.