| Summary: | 碩士 === 國立交通大學 === 電子物理系所 === 103 === We have studied that chalcopyrite CuInSe2 thin films were grown on GaN (000±1) by molecular beam epitaxy (MBE). Atomic Force Microscopy (AFM) was used for characterizing the surface morphology and surface roughenss. Cu-rich CIS has a bigger grain size and surface roughenss. The band gap of Cu-rich CIS and In-rich CIS were evaluated by spectrophotometer. The absorption edge of Cu-rich CIS is at 1187 nm, which equals to the band gap of 1.045eV. The absorption edge of In-rich CIS is at 1166 nm, which equals to the band gap of 1.063eV. X-ray diffraction showed that the CuInSe2 thin film was grown in (112) orientation. The Cu-rich CuInSe2’s peak of rocking curve with full width at half maximum of about 897.8 arcsec indicated the epitaxial growth of Cu-rich CuInSe2(112) film on N-face GaN substrate. Microstructure analysis of the CuInSe2 showed that the large lattice mismatch (28.5%) between CuInSe2 and GaN is accommodated by domain epitaxy, and domain mismatch is about 2.8%. We found that there has no interface reaction or diffusion occurs between CuInSe2 and GaN by Energy-Dispersive Spectroscope(EDS). Our experimental results show that the heteroepitaxially grown CuInSe2 on GaN is stable, which exhibits a great potential for optoelectronic applications.
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