本論文主要研究為利用熔融體生長法 (Liquid phase growth) 成長層狀化合物半導體-硒化銦摻雜鎘原子系列 (InSe:Cd x%, x=0.5, 1, 5) 和硒化銦摻雜錫原子系列 (InSe:Sn x%, x=5) 之晶體，並針對二摻雜硒化銦系統晶體進行結構分析、光學與電學量測來 探討摻雜原子對化合物的影響。首先藉由能量色散 X 射線光譜 (Energy dispersive Xray spectroscopy, EDS) 確認元素比例與預期計算相符後，透過 X 射線光電子能譜 (Xray photoelectron spectroscopy, XPS) 觀察到 Cd 及 Sn 皆有摻入 InSe 中，且從 InSe:Cd 系列晶體可知，當 Cd 摻入愈多，使價帶 (Valence band, VB) 與費米能階的距離愈近。 從 X 射線粉末繞射圖 (X-ray diffraction analysis, XRD) 和高解析電子顯微圖 (Highresolution transmission electron microscopy, HRTEM) 的結果可確定 InSe:Cd 系列和 InSe:Sn 系列皆為六方晶系，而摻雜物並未對結構造成變化。在拉曼光譜觀察到每個 晶體都有相同的振動模態。光學量測中，藉由熱調制反射光譜 (μ-Thermoreflectance, μTR) 測出所有材料皆為直接能隙半導體，在 300 K 時能隙位置位於 1.238~1.242 eV ， 此外在 10 K 之顯微光激發螢光光譜 (μ-Photoluminescence, μPL) ，可以觀察到 3 個激 子訊號，其中 M、SX 可合稱為複合束縛激子群，其中 SX 為表面之帶電性的雜質束 縛激子，其強度隨溫度衰減最快，和 M 隨溫度升高而逐漸合一再衰弱；FX 為自由 激子，隨溫度升高而紅移且強度隨溫度緩慢衰減。在電學量測熱探針與霍爾量測中， 可以測得 InSe 和 InSe:Sn 5% 為 n 型半導體，而 InSe:Cd 系列則變成 p 型半導體。在 V-I 以及范德堡法量測中發現 Cd 的加入，使 InSe:Cd 系列的電阻率增加。因 InSe 在 光電器件方面有廣泛應用，最後我們從中選擇 n-type 的 InSe:Sn 5% 與 p-type 的 InSe:Cd 0.5% 做初步的 InSe 同質接面 (Homojunction) 元件，除透過 V-I 量測出 p-n 接 面元件的二極體曲線外，我們外加電流時可發出 1.22 eV 的光，有做為紅外光 LED 的潛力。

Indium selenide (InSe) has a potential in the fields of optoelectronic devices and integrated circuits. This study is about layered semiconductor InSe doped with tin (InSe:Sn 5%) and InSe doped with cadmium (InSe:Cd 0.5% , InSe:Cd 1%, InSe:Cd 5%) which grown by liquid phase growth. The structural analysis, optical and electrical measurements are carried out for dopant series crystals to explore the effect of dopant atoms on the compound. The energy dispersive X-ray spectroscopy (EDS) & X-ray photoelectron spectroscopy (XPS) confirmed the element ratio. The XPS spectra of Cd series displayed that the valence band shifted to higher as Cd composition increase, resulting in the peak shifting. From X-ray diffraction (XRD) spectra and transmission electron microscope (TEM) image, the crystal structure was hexagonal, and the lattice constant didn’t change significantly as Sn or Cd is doped inside InSe. The μRaman spectra revealed that all the crystals have 6 vibration modes. Optical properties of InSe:Sn 5% and Cd series were characterized using micro-thermalmodulated reflectance (μTR), and the direct bandgap ranging from 1.238-1.242 eV was obtained at 300 K. The band-edge emission features were carried out by temperature dependent micro-Photoluminescence (μPL). At 10 K the bound excitons complex/BECs (M, SX) and free exciton (FX) appeared. The hot probe and Hall measurement showed that InSe and InSe:Sn 5% are n-type, and all InSe:Cd series changed to p-type semiconductors. The resistivity of the InSe:Cd series became higher as Cd composition increased proven by V-I and van der Pauw experiment, meanwhile the resistivity of the InSe:Sn 5% didn’t change. In this work, we selected n-type InSe:Sn 5% to stack with p-type InSe:Cd 0.5% to make homojunction. The p-n junction displayed the diode curve with electroluminescence (EL) at 1.22 eV.

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