Study of electrical and optical properties of amorphous Si film dopped with P and B prepared by thermal evaporation

This research includes the electrical and optical properties of amorphous silicon films prepared by thermal evaporation and doped with phosphor and boron, to obtain n- and p-type X-ray analysis showed that films prepared in the temperature range 303-650 K and annealed at various temperatures up to 650 K are of amorphous structure. The activation energy was not a single value through the annealing process. There were three activation energies for either n- or p-type. For a Si+1.5% p (i.e. n-type) the activation energies were 0.606, 0.498 and 0.345 eV for the temperature ranges (415-483), (382-415) and (313-382) K respectively. These results have been interpreted on the basis of the existence of three different mechanisms of conduction through the mentioned above temperature range of annealing. It has been found that their films of 600 nm thickness prepared with 2.5 nm/sec, showed a significant increase in conductivity; for n-type (0.6-12,2x10-4Ω-1. cm-1 and for p-type 0.4-8)x10-4Ω-1.cm-1 in the thickness range (200-600) nm, this is because the scattering effect at the surface is weak for big thickness. 36 figs.; 11 tabs.; 40 refs