Performances of Nano/Amorphous Silicon Films Produced by Hot Wire Plasma Assisted Technique

ABSTRACTThis work reports on the performances of undoped and n doped amorphous/nano-crystalline silicon films grown by hot wire plasma assisted technique. The film's structure (including the presence of several nanoparticles with sizes ranging from 5 nm to 50 nm), the composition (oxygen and hydrogen content) and the transport properties are highly dependent on the filament temperature and on the hydrogen dilution. The undoped films grown under low r.f. power (≍ 4 mWcm−2) and with filament temperatures around 1850 °K have dark conductivities below 10−1Scm−1, optical gaps of about 1.5 eV and photo-sensitivities above 105, (under AM3.5), with almost no traces of oxygen content. N- doped silicon films were also fabricated under the same conditions which attained conductivities of about 10−2Scm−1.