Phosphor-doped nano-crystalline silicon ((n))nc-Si:H) films are successfully gro wn on the p-type (100) oriented crystal silicon ((p) c-Si) substrate by conventi onal plasma-enhanced chemical vapor deposition method. The films are obtained us ing high H2 diluted SiH4 as a reaction gas source and usin g PH3 as the doping gas source of phosphor atoms. Futhermore, the het erojunction diodes are also fabricated by using (n)nc-Si:H films and (p)c-Si sub strate. I-V properties are investigated in the temperature range of 230—420K. T he experimental results domenstrate that (n)nc-Si:H/(p)c-Si heterojunction is a typical abrupt heterojunction having good rectifing and temperature properties. Carrier transport mechanisms are tunneling-recombination model at forward bias v oltages. In the range of low bias voltages (VFF>1.0V). The present heterojunction has high reverse breakdown voltage (>-75V) and low re verse current (≈nA).