2010, Vol.20, No.1

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

CuInGaSe(CIGS) mixed-source was prepared by hydride vapor phase epitaxy (HVPE). Each metal was mixed in regular ratio and soaked at 1090oC for 90 minutes in nitrogen atmosphere. After making the mixed-source to powder state,the pellet was made by the powder. The diameter of pellet is 10 mm. The CIGS thin film was deposited on soda lime glass evaporated Mo layer by e-beam evaporator. To confirm the crystallization, we measured X-ray diffraction (XRD). High intensity X-ray peaks diffracted from (112), (204)/(220), (116)/(312) and (400) of CIGS thin film and from (110) of Mo were confirmed by XRD measurement.

The reduction of optical losses in mono-crystalline silicon solar cell by surface texturing is a critical step to improve the overall cell efficiency. In this study, we have changed the sub-micrometer structure on the micrometer pyramidal structure by 2-step texturing. The Ag particles were coated on the micrometer pyramid surface in AgNO3solution, and then the etching with hydrogen fluoride and hydrogen peroxide created even smaller nano-pyramids in these pyramids. As a result, we observed that the changes of size and thickness of nano structure on pyramidal surface were determined by AgNO3 concentration and etching time. Using 2-step texturing, the surface of wafers is etched to resemble the rough surface of a lotus leaf. Lotus surface can reduce average reflectance from 10 % to below 3 %. This reflectance is less than conventional textured wafer including anti-reflection coating.

Metamictization and color change in zircons from Cambodia and Tanzania were investigated. Elements analysis to detect radioactivity of elements such as U and Th, and spectroscopic analysis using UV-VIS and Fourier transform infrared spectroscopy were performed. According to the UV-VIS spectroscopic analysis, it was perceived that many and high intense absorption peaks appeared in blue and colorless zircons, while less and low intense absorption peaks appeared in uranium contained green and yellow zircons. It was found that those stones have made progress to the metamictization. After heat treatment, we could detect opposite results. As the results of FTIR spectroscopy analysis, in the metamict green and yellow zircon, it is showed that 3-phonon combination mode bands of [SiO4]4− internal vibration in the region of 3100~3400 cm−1are broad and some of them disappear. However, the disappeared bands are observed again due to restored crystal lattice by the heat treatment. Also, U 4+peaks that can detect the uranium content in zircon appears at near 4800 cm−1in the green and yellow samples. From this investigation, we could observe the metamictization effect and color change in uranium-bearing zircon by heat treatment using spectroscopic analysis.