本論文成功合成出三種新穎的金屬硫族化合物K1.00Zn1.46(1)Se2.00 (1)、K1.00Mg0.22(3)Zn1.28(2)Se2.00 (2) 、K1.00Mg0.27(2)Zn1.23(1)Se2.00 (3)，並著重
化合物2的結構及光學特性來介紹。化合物 2的結構屬於對稱中心的點群，其晶系及空間群為Monoclinic P21/n，而單位晶格的軸長為a = 7.4614(2) Å，b = 5.9685(2) Å，c = 10.9680(3) Å，V = 467.65(2) Å3。此化合物之結構由混填MgZn陽離子與Se陰離子以四面體形成二維的層狀結構，沿著b軸無限延伸排列，K陽離子則是參雜在層與層之間。
化合物 2之純相合成方法如下，將反應物在800°C高溫初步熔融後，以每小時降溫5ºC至500ºC，即可獲得純相。以熱差分析儀測定其熔點為552 oC，再結晶點為531 oC。本化合物之能隙值由紫外光可見光近紅外光吸收光譜儀鑑定為直接能隙2.27 eV。經由KP&APS系統測量屬於p型半導體。利用波長458nm的雷射光照射後，在615 nm附近有強烈的光致放光訊號，意味著此化合物除了在紅外非線性光學材料具有潛力外，也有機會製作成太陽能電池中的吸收層。目前正在進行三倍頻量測以及將化合物 2製作成不同厚度的薄膜，期許能夠有良好的太陽能轉換效率。

Three novel metal chalcogenides of (1) K1.00Zn1.46(1)Se2.00 (2) K1.00Mg0.22(3)Zn1.28(2)Se2.00 (3) K1.00Mg0.27(2)Zn1.23(1)Se2.00 have been synthesized by solid-state reaction at 800 oC. We will focus on structural and optical properties of compound 2. Compound 2 crystallizes in a centrosymmetric space group of Monoclinic P21/n with cell parameters a = 7.4614(2) Å, b = 5.9685(2) Å, c = 10.9680(3) Å ,V = 467.65(2) Å3, and Z = 4. The structure of this compound is constructed by MSe4 tetrahedra (M = Mg/Zn) to form a two-dimensional layered structure. The layers are stacking along the b axis while K+ cations are inserted between layers. Due to distorted structure, it has a potential to become infrared nonlinear optical material. The band gap measured by UV-vis-NIR absorption spectra is estimated to be around 2.27 eV, which belongs to a direct band gap material as further analyzed by the Kubelka-Munk function. The differential thermal analysis of compound 2 shows melting point around 552 ºC and recrystallization point around 531 ºC. The single crystal displays a strong photoluminescence signal near 615nm using an incident laser at 458 nm. Therefore, it has the potential to be made into an absorber layer in solar cells. Finally, the third harmonic generation (THG) measurement of compound 2 is in progress and it is made into thin films of different thickness, hoping to have a good solar energy conversion efficiency.

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