TRANSPARENT CONDUCTING BORON-DOPED ZINC-OXIDE FILMS DEPOSITED BY DC-MAGNETRON SPUTTERING IN B2H6-AR MIXTURES

Transparent conducting ZnO:B films for solar cells were produced by DC magnetron sputtering in B2H6-Ar mixtures. Low-resistivity textured films could be obtained at relatively low substrate temperatures of 150-200 degrees C. The resistivity, electron mobility and carrier concentration were 4 x 10(-4) Omega cm, 60 cm(2)/Vs and 2 x 10(20) cm(-3), respectively. The 2-mu m-thick films showed a sheet resistance of 2 Omega/sq and optical transmission of greater than 85% at wavelengths of 0.6-1.0 mu m. These films exhibited higher optical transmission in the near infrared region than ZnO:Al films with the same resistivity because of high electron mobility. No degradation of resistivity and optical transmission was observed after exposure at 85 degrees C and 95%RH for 5 h.