Atmospheric pressure chemical vapor deposition of textured zinc oxide, doped titanium dioxide, and doped zinc oxide thin films

Atmospheric pressure chemical vapor deposition of several thin film materials is described.; Textured ZnO films were deposited as a textured antireflection layer on polysilicon solar cells using diethylzinc and water as the precursors. We were able to deposit textured ZnO films of high optical transmittance at a low temperature (250{dollar}spcirc{dollar}C) with high growth rates (up to 4000A/minute), and good uniformity and reproducibility. The improved efficiencies on polysilicon solar cells were mainly due to increase in the short circuit currents.; Conductive niobium and hydrogen doped titanium dioxide films were deposited from titanium isopropoxide, niobium ethoxide and cyclohexenone. An ultrasonic atomizer nozzle was used to vaporize the precursor. Deposition temperature ranged form 450{dollar}spcirc{dollar}C to 560{dollar}spcirc{dollar}C. Film resistivity had a strong dependence on film thickness up to 1.5 {dollar}mu{dollar}m. At a film thickness of 3 {dollar}mu{dollar}m, a low resistivity of {dollar}3times 10sp{lcub}-3{rcub} Omega{dollar} cm was achieved for the niobium doped films. The mobility was about 0.6-0.7 cm{dollar}sp2{dollar}/Vs. The electron concentration was about 2-3 {dollar}times{dollar} 10{dollar}sp{lcub}21{rcub}{dollar}/cm{dollar}sp3.{dollar} A thin layer of niobium doped titanium dioxide was deposited on fluorine doped tin oxide to study its application as a protection layer on solar cells. The niobium doped films had high visible absorption. The hydrogen doped films had lower visible absorption. The resistivity of the hydrogen doped films were as low as the niobium doped films, but the resistivity increased with time. The mobility of the hydrogen doped films was about 12-20 cm{dollar}sp2{dollar}/Vs. The electron concentration was about 5-8 {dollar}times{dollar} 10{dollar}sp{lcub}18{rcub}{dollar}/cm{dollar}sp3.{dollar}; Transparent conducting fluorine and aluminum doped zinc oxide thin films were deposited from tetramethylethylenediamine diethylzinc, ethanol, benzoyl fluoride, {dollar}rm Etsb3Alsb2(Osp{lcub}rm S{rcub}Bu)sb3,{dollar} and Al({dollar}beta{dollar}-diketonate). The films were polycrystalline and highly oriented with the c-axis perpendicular to the substrate. The aging time of the precursor affected the electrical and optical properties of the films. The resistivity of the films was as low as {dollar}4times 10sp{lcub}-4{rcub} Omega{dollar}cm. The mobility was as high as 45 cm{dollar}sp2{dollar}/Vs. The optical absorption of the films was as low as 3% at a sheet resistance of 7 {dollar}Omega /square .{dollar} The diffuse transmittance was up to 20% at 6500A. Amorphous silicon solar cells were deposited on textured fluorine doped zinc oxide. The short circuit current improved over cells made with fluorine doped tin oxide due to the superior optical properties.