Electrical properties of phosphorous-doped n-type poly-crystalline beta-irondisilicide have been studied by preparation of heterojunctions with p-type silicon. The phosphorous-doped poly-crystalline beta-irondisilicide films prepared by sputtering of Si, Fe and Fe3P show higher conductivity than undoped one and indicate n-type conductivity by thermoelectric power measurement. The heterojunctions show rectifying characteristics at various doping level, although the devices show large backward leak current. These results indicate that the phosphorous doping by co-sputtering of Si, Fe and Fe3P change the conductivity of the films to n-type. (C) 2002 Elsevier Science Ltd. All rights reserved.