npsm 새물리 New Physics : Sae Mulli

pISSN 0374-4914 eISSN 2289-0041


Research Paper

New Physics: Sae Mulli 2017; 67: 915-921

Published online August 31, 2017

Copyright © New Physics: Sae Mulli.

Studies of the Crystal Structure and Optical Properties of Zn$_{0.95}$Mn$_{0.05}$S Epilayers

Zn$_{0.95}$Mn$_{0.05}$S 단결정 박막의 결정구조와 광학적 특성 연구

Dae Jung KIM*1, Bong Jin KIM1, Duk Hyeon KIM1, Jong Won LEE2

1 School of Basic Sciences, Hanbat National University, Daejeon 34158, Korea
2 Advanced Materials Engineering, Hanbat National University, Daejeon 34158, Korea


Received: February 10, 2017; Revised: April 7, 2017; Accepted: April 28, 2017

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


Zn$_{0.95}$Mn$_{0.05}$S epilayers were grown on GaAs (100) substrates by using the hot-wall epitaxy method. X-ray diffraction was used to study the crystallinity and the crystal orientation of the epilayer. The surface morphology of the epilayer was observed by scanning electron microscopy-energy dispersive X-ray spectrograph (SEM-EDS). The optical properties of the epilayers were investigated in a wide photon energy range between 2.0$\sim$8.7 eV by using spectroscopic ellipsometry (SE) and were studied in the transmittance spectra in the wavelength range from of 400 to 700 nm at room temperature. The obtained data were analyzed to find both the critical points of the pseudodielectric function spectra, $<\varepsilon(E)>$ = $<\varepsilon_1(E)> + i<\varepsilon_2(E)>$, such as $E_0/E_0 +\Delta_0$, $E_1$, and the three $E_2(\Sigma, \Delta, \Gamma)$ structures. Also, the pseudodielectric-function-related optical constants of Zn$_{0.95}$Mn$_{0.05}$S, such as the $\alpha(E)$, were analyzed. The optical energy band gap, $E_g$ = 3.72 eV, was determined from the transmittance spectrum of the free-standing film and was compared with the calue of $E_0$ = 3.80 eV obtained from the SE measurement.

Keywords: ZnMnS, XRD, SEM-EDS, Spectroscopic ellipsometry, Hot-wall epitaxy, Pseudodielectric function, Transmittance

Zn$_{0.95}$Mn$_{0.05}$S 단결정 박막은 열벽적층 성장법(hot-wall epitaxy, HWE)을 이용하여 GaAs (100) 기판 위에 성장시켰다. 성장된 박막의 결정구조는 엑스선 회절 패턴을 이용하여 알아보았고, 박막의 표면 상태와 성분비는 에너지 분해가 가능한 엑스선 분광장치가 달린 주사전자 현미경을 이용하여 측정하였다. 성장된 박막의 정확한 광학적 에너지 밴드 갭은 투과율이 400$\sim$700 nm 범위에서 실온상태로 측정하여 획득하였다. 또한 박막의 광학적 특성은 분광학적 타원 편광 분석법으로 실온에서 2.0$\sim$8.7 eV 사이 포톤에너지 범위에서 측정하여 알아보았다. 측정된 데이터들은 유사유전함수 스펙트럼 $<\varepsilon(E)>$ = $<\varepsilon_1(E)> + i<\varepsilon_2(E)>$에 나타난 $E_0/E_0+\Delta_0$, $E_1$, 그리고 세 개의 $E_2(\Sigma, \Delta, \Gamma)$와 같은 임계점 구조에 대하여 연구하였다. 또한 박막은 복소 유전함수와 밀접한 관계를 가지고 있는 $\alpha(E)$와 같은 광학적 특성에 관하여 연구하였다. 정확한 광학적 에너지 밴드 갭은 GaAs 기판을 제거한 순수한 박막의 흡수스펙트럼으로부터 $E_g$ = 3.72 eV로 결정되었고, 그 결과를 타원 편광 분석법에 의하여 측정된 $E_0$ = 3.80 eV와 비교하였다. 

Keywords: ZnMnS, 엑스선 회절 패턴, 주사전자 현미경, 타원 편광 분석법, 열벽적층 성장법, 유사유전함수, 투과측정

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