2012, Vol.22, No.2

Journal of the Korean Crystal Growth and Crystal Technology 2023 KCI Impact Factor : 0.19

pISSN : 1225-1429 / eISSN : 2234-5078
https://journal.kci.go.kr/jkcgct

Aluminum induced crystallization of amorphous silicon was attempted by the aluminum substrate. To avoid the layer exchange between silicon and aluminum layer, Ni layer was deposited between these two layers by sputtering. To obtain the bigger grain of the crystalline silicon, wet blasted silica layer was employed as windows between the nickel and a-Si layer. Ni obtained after the annealing treatment at 520oC was found to be a promising material for the diffusion barrier between silicon and aluminum. One way to obtain bigger grain of crystalline silicon layer applicable to solar cell of higher performance was envisioned in this investigation.

Co-(0.8 wt%) and Ce-(0.4 wt%) doped cubic zirconia (ZrO2 : Y2O3 = 80 : 20, 70 : 30, 60 : 40, 50 : 50 wt%) single crystals grown by a skull melting method were heat-treated in N2 at 1000oC for 5 hrs. The orange, yellowish brown and brown colored as-grown single crystals were changed into either brownish red, yellow and green color after the heat treatment. Before and after the heat treatment, the YSZ (yttria-stabilized zirconia) single crystals were cut for wafer form (φ6.5 mm × t2 mm). The optical and structural properties were examined by UV-VIS spectrophotometer and X-ray diffraction. Absorption by Ce3+(2F5/2, 7/2(4f) → 2Tg(5d1)), Co2+(4A2(4F) → 4T1(4F) or 4T1(4P)) and Co3+, change of ionization energy and lattice parameter were confirmed.

The structural change and the electrical conductivity with Sr content in La1 − xSrxMn0.8Cu0.2O3 (LSMCu) were studied. La0.8Sr0.2MnO3 (LSM) and La1 − xSrxMn0.8Cu0.2O3 (0.1 ≤ x ≤ 0.4) were synthesized by EDTA citric complexing process (ECCP). A decrease in the lattice parameters and lattice volumes was observed with increase of Sr content, and these results were attributed to the increasing Mn4+ ions and Cu3+ ions in B-site. The electrical conductivity measured from 500oC to 1000oC was increased with increase of Sr content in the 0.1 ≤ x ≤ 0.3 composition range, and it was 172.6 S/cm (at 750oC) and 177.7 S/cm (at 950oC, the maximum value) in x = 0.3. The electrical conductivity was decreased in x = 0.4because of the presence of the second phase in the grain boundaries. The lattice volume was contracted by increase of Mn4+ ions and Cu3+ ions in B-site according to increase of Sr content and the electrical conductivity was increased with increase of charge carriers which were involved in the hopping mechanism.