The effects of boron and phosphorous ion implantation in C60 thin films

The boron and phosphorous ion implantation effects on electron and optical property of C₆₀ thin film are studied for fabricating new solar cells made from carbon. C₆₀ thin film changes to the amorphous carbon due to boron or phosphorous implantation. The resistivity of the thin films can be controlled by changing amount of dose, and a value of (10-1 Ω·cm) for a thin film solar cell is achieved. The conduction of P-ion implanted films is determined by the variable range hopping at low temperature. The density of states at the Fermi level N(E_F) is more than 9.0×10¹⁹ (cm³ eV^-1), which is estimated using Mott´s equation, indicating that there are a large amount of defects in the film. Absorption edge of B and P-ion implanted C₆₀ film is changed to the low photon energy as ion dose increases