本論文利用光調製反射光譜與光激發螢光光譜來分析氧硒化鋅合金的直接能隙，氧濃度為0~0.07。在室溫下，能隙隨著氧濃度上升會大幅度地縮小，此結果符合能帶互斥理論。在溫度150~300K的範圍內，由能帶互斥理論推算出的氧濃度與X光繞射實驗的結果相近。然而，在低溫10~150K的範圍內，出現了能隙隨溫度變化趨勢增大的現象，變化趨勢往主材料硒化鋅接近，而偏離了能帶互斥理論。實驗結果在低溫偏離能帶互斥理論的現象，可能與氧硒化鋅合金之局域態特性所造成的影響有關。

This thesis mainly focuses on the direct band gap analysis of ZnSe1-xOx alloys (x=0~0.07) through photoreflectance (PR) spectroscopy and photoluminescence (PL) spectroscopy. The band gap of alloys decreases significantly with increasing oxygen concentration at room temperature, which agrees with the band anticrossing model (BAC). In higher temperature range (150~300K), the BAC model well predicts the oxygen concentration which consists with experimental results under X-Ray diffraction (XRD) examination. However, when the temperature is under 150K, BAC model underestimates the drastic band gap tendency which is closer to the behavior of the host material ZnSe. This deviation from BAC model may associate with the localized state properties of ZnSe1-xOx alloys.

[1]W. G. Bi et al., “Bowing parameter of the band-gap energy of GaNxAs1-x”, Appl. Phys. Lett. 70 1608 (1997)
[2]W. Shan et al., “Band Anticrossing in GaInNAs Alloys”, Phys. Rev. Lett. 82 1221 (1999)
[3]W. Shan et al., “Band Anticrossing in Dilute Nitrides”, J. Phys.: Condens. Matter 16 S3355–S3372 (2004)
[4]John P. Walter and Marvin L. Cohen, “Calculation of reflectivity, modulated reflectivity, and band structure of GaAS, GaP, ZnSe, and ZnS”, Phys. Rev. 183, 3 (1969)
[5]Y. Nabetani et al., “Epitaxial growth and large band-gap bowing of ZnSeO alloy”, Appl. Phys. Lett. 83 1148 (2003)
[6]J. A. VanVechten et al., “Electronic structures of semiconductor”, Phys. Rev. B 1, 3351 (1970)
[7]D. Richardson et al., “The effect of atomic displacement on energy gap bowing in zincblende semiconductor alloys”, J. Phys. C 5, 821 (1972)
[8]K. Uesugi et al., “Temperature dependence of band gap energies of GaAsN alloys”, Appl. Phys. Lett. 76 1285 (2000)
[9]C.-Y. Chen et al ., “Optical properties of ZnSe1-xOx epilayers”, Electronics Letters Vol. 45 No. 24 (2009)
[10]陳星宏,“氧硒化鋅薄膜之光學特性研究”, 國立中央大學 物理學系 碩士論文
[11]A. Polimeni et al., “Temperature dependence and bowing of bandgap in ZnSe1-xOx”, Appl. Phys. Lett. 84 3304 (2004)
[12]W. Shan et al., “Effect of oxygen on the electronic band structure in ZnSe1-xOx alloys”, Phys. Rev. Lett. 82 1221 (2003)
[13]Y. Nabetani et al., “Structure and optical properties of ZnSeO alloys with O composition up to 6.4%”, Materials Science in Semiconductor Processing 6 ,343–346 (2003)
[14]L. Malikova et al., “Temperature dependence of the direct gaps of ZnSe and Zn0.56Cd0.44Se”, Phys. Rev. B, 54 1819 (1996)