2014, Vol.24, 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

Three kinds of crystalline silicon have been used for the solar cell grade. First of all, single crystalline silicon isthe main subject to enhance the production yield. Most of the efforts are focused on the control of the melt-crystalinterface shape affected by the crystal-crucible rotation rate. The main subject in the multi-crystalline silicon ingot is thecontamination control. Faster Ar gas flow above the melt surface will lower the carbon contamination in the crystal. Andalso, twin boundary electrically inactive is found to be more effective than grain boundary for the improvement of theMCLT. In the case of mono-like silicon material, propagation of the multi-crystalline silicon growing from the inner sidecrucible is the problem lowering the portion of the single crystalline part at the center of the ingot. Crystal growingapparatus giving higher cooling rate at the bottom and lower cooling rate at the side crucible was suggested as theoptimum solution obtaining higher quality of the mono-like silicon ingot. Proper application of the seeds at the bottom ofthe crucible would be one of the solutions.

AlN (Aluminum Nitride) crystals were grown by a PVT (Physical Vapor Transport) method and were characterizedto phases on the growth temperature. The crystals phase and morphology were analyzed using an optical stereo-microscopeand the optimum temperature for the growing was determined. In this report, the characteristics of the AlN crystals grownat various temperatures were reported.

Crystallographic phases of Plasma electrolytic oxidized Al alloy, A1050, were investigated. The electrolyte ofPEO was Na2Si2O3 and KOH. Unipolar pulse, 2000 μsec with 400 μsec + 420 V impulse, were applied for 2 min, 5 min,15 min, and 30 min. γ-Alumina, as well as α-alumina, was main crystal phase. γ-Alumina was appeared in the beginning,then the amount of α-alumina was increased with time, but the amount of γ-alumina remained constant without anyincreasing. So, it is concluded that plasma gas produce γ-alumina at the first, and then γ-alumina transform α-aluminafinally. During the transformation, high temperature of micro plasma gives transformation energy.