The effects of boron and phosphorous ion implantation in C/sub 60/ thin films

Abstract

The boron and phosphorous ion implantation effects on electron and optical property of C/sub 60/ thin film are studied for fabricating new solar cells made from carbon. C/sub 60/ 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 /spl Omega//spl middot/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/sub F/) is more than 9.0/spl times/10/sup 19/ (cm/sup 3/ eV/sup -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 C/sub 60/ film is changed to the low photon energy as ion dose increases.