本論文題目所用的Zn2P2S6和Ni2P2S6晶體為本實驗室用化學氣相傳導法(Chemical vapor transport method, CVT)生長，為層狀單晶材料，屬於過渡性金屬硫屬磷酸鹽系列晶體，該系列晶體材料能隙涵蓋範圍甚廣，可從紫外光波長至紅外光波長，因此現今許多學者對這系列材料有極大的興趣並研究與探討，期許在這類較新穎的材料中能有突破性的發展與應用。
而本論文中選用Zn2P2S6和Ni2P2S6來進行一系列的結構分析與光學特性研究，Zn2P2S6為寬能隙半導體，Ni2P2S6為低能隙半導體。首先我們會進行材料的結構分析，包括X射線能量散佈分析儀(EDS)、X射線晶體繞射分析儀 (XRD)以及拉曼光譜實驗。EDS可以分析出晶體的原子比例，確保我們成長出的單晶晶體品質，以利之後量測實驗分析的可信度。從X-ray晶格繞射分析結果，可以得知此兩種晶體皆屬於單斜結構，藉由布拉格繞射公式及單斜晶體公式計算出兩者的晶格常數。Zn2P2S6的晶格常數a=5.966Å , b=10.32Å, c=6.717Å，Ni2P2S6為a=5.741 Å , b=10.05 Å , c=6.576 Å。將這兩晶體的晶格常數互相比較，因為具有相同結構M2P2S6，可以發現晶格常數相似，而造成Zn2P2S6比Ni2P2S6的晶格常數大的原因是因為Zn(原子序=30)比Ni(原子序=28)原子具有較大的原子半徑。在拉曼光譜實驗可以比較兩者的振動模態，之後在結果與討論會詳細分析兩者之間有什麼相同的振動模態以及不同之處進行比較。
在光學量測實驗中，我們做了熱調制實驗與光穿透實驗，透過這兩種實驗可以得知兩種材料的激子躍遷訊號，Zn2P2S6的室溫躍遷訊號在3.438V，在低溫30K移至3.658eV；而Ni2P2S6的室溫躍遷訊號在1.362eV，低溫15K移至1.474eV，並且在低溫還可觀察到額外兩個激發訊號位在1.492eV和1.538eV。比較兩種不同機制的光學實驗有利於我們得到更完整的資訊。最後在熱探針實驗部分，利用載子濃度梯度的變化，我們可以得知Zn2P2S6為n-type半導體，Ni2P2S6為p-type半導體。
本論文對Zn2P2S6及Ni2P2S6的材料分析與光學特性研究，相信對有共同興趣的學者可以提供有用的參考資料，以利未來在材料應用上能有突破的發展。
 

Transition metal phosphorus trichalcogenides (TMPTs) have recently started to attract interest, since the bulk TMPTs possess band gaps in a range of 1.3−3.5 eV, from the wavelength of ultraviolet light to the wavelength of infrared light. Therefore, many scholars have studied and discussed this series of materials, and hope to have breakthrough development and application in such relatively novel materials. In this thesis, M2P2S6(M=Zn, Ni) layered single crystal series have been grown by Chemical vapor transport (CVT) method using Iodine (I2) as transport agent. These materials has been classified as TMPTs materials belonging to family with a structural formula of MPX3(M=V, Mn, Fe , Ni, Cd, Zn; X=S, Se). In this thesis, Zn2P2S6 and Ni2P2S6 were selected for a series of structural analysis and optical characterization. The structural analysis of Zn2P2S6 and Ni2P2S6 were identified using Energy Dispersive X-ray Spectroscopy (EDS), X-ray Diffraction (XRD), and Raman spectroscopy. From analyzing XRD pattern, these series crystal are determined to be crystallized in monoclinic structure, and the lattice constants of the two crystals are calculated by the Bragg diffraction formula and the monoclinic crystal formula. The lattice constants of Zn2P2S6 are a = 5.966 Å, b = 10.32 Å, c = 6.718 Å, and Ni2P2S6 are a = 5.741 Å, b = 10.05 Å, and c = 6.576 Å. By comparing the lattice constants of these two crystals, it can be found that the lattice constant of Zn2P2S6 is larger than Ni2P2S6 owing to Zn (Z = 30) has a larger atomic radius than Ni (Z = 28) atoms. In Raman spectroscopy, the vibration modes of Zn2P2S6 and Ni2P2S6 can be observed, and we can compare the similarities between these two materials. Optical properties of Zn2P2S6 and Ni2P2S6 have been characterized using temperature dependent Thermoreflectance (TR) and the absorption measurement. By comparing optical absorption and thermoreflectance spectra at room temperature, we can determine the band gap of M2P2S6(M=Zn, Ni) at 3.438V and 1.362eV, respectively. The difference of carrier concentration has been calculated using Hot probe measurement and it shows that Zn2P2S6 is n-type conductivity materials while Ni2P2S6 is p-type conductivity.This studies demonstrate the material analysis and optical properties of Zn2P2S6 and Ni2P2S6. We believe that this paper can provide useful information for scholars with common interests.

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