COMPENSATION EFFECTS IN C-60 DOPED BY ION-IMPLANTATION

We have studied electrical transport phenomena after ion implantation in sublimed C-60 films. A n type doping exists with 30 KeV potassium i on irradiations and low fluences (D < 10(15)ions/cm(2)). However degra dation effects have been noted. So we have tried to discriminate dopin g and damage effects. Studies about the compensation phenomenum have b een performed in order to prove the chemical role of the potassium ato ms. An electron transfer from the alkali metal is sure; but a strong c ompetition exists between degradation and doping phenomena. Finally, t he intact C-60 molecules are the insulator barriers, K3C60 and isolate d carbon atoms are the conductor phase for an heterogeneous media mode l.