本文選題：一維氧化鋅納米材料 + 納米發(fā)電機��； 參考：《北京科技大學》2015年博士論文

【摘要】：氧化鋅(ZnO)納米材料同時具備優(yōu)異的半導體性能和壓電性能。利用維ZnO納米材料的壓電性能構建的壓電納米發(fā)電機和半導體與壓電的耦合特性構建的壓電電子器件已成為納米半導體器件研究領域的新方向。以應用為導向,利用材料的結構特點構建高性能的實用性壓電電子器件,探究壓電電子效應對器件界面處載流子行為的調控規(guī)律等,已成為當前的研究熱點。 本研究通過優(yōu)化生長工藝,控制合成出多種一維ZnO納米材料。構建了單根銦摻雜氧化鋅(In-ZnO)納米帶柔性應變傳感器,利用有限元模擬分析了器件的應變響應機理；構建了ZnO納米線陣列振動傳感器,研究了在自驅動模式和外加電壓模式器件的響應機理,實現了低頻機械振動信號的探測,并應用于人體脈搏振動的探測；構建了Pt/Al2O3/ZnO肖特基結,研究了應變對器件界面電阻、接觸勢壘以及界面光生載流子的調控規(guī)律,揭示了壓電電子效應對載流子的界面調控機制。 采用氣相沉積法制備了In-ZnO納米帶,納米帶寬度約為1μm、厚度約為200nm、長度大于100μm,生長方向為[2110],上表面為(0001)極性面。采用水熱合成法通過工藝優(yōu)化制備了高度為10μm的ZnO納米線陣列和高密度ZnO納米線陣列薄膜。采用氫氧化鈉和醋酸鋅的乙醇溶液交替涂覆,在柔性襯底上制備了ZnO晶種層,生長了ZnO納米線陣列。 采用In-ZnO納米帶構建了柔性壓電電子應變傳感器,分別實現了靜態(tài)和動態(tài)應變檢測。器件的電流電壓曲線呈雙肖特基整流特性。靜態(tài)應變檢測時,電流電壓曲線在壓縮應變時上移,拉伸應變時下移。采用有限元模擬分析了In-ZnO納米帶在軸向應變下的壓電勢分布,發(fā)現在泊松效應的作用下,軸向應變使In-ZnO納米帶在極性上表面產生壓電勢,調控了源漏極肖特基勢壘高度,產生應變響應電流。周期性應變動態(tài)檢測結果說明器件具有清晰準確的響應電流,壓縮應變時應變系數達到4036。 采用柔性Pt電極與ZnO納米線陣列構建了肖特基型振動探測器。器件可在無外加工作電壓的自驅動模式和外加工作電壓模式實現對低頻機械振動信號的探測。自驅動模式中,器件的響應電流是通過納米線陣列產生的壓電勢改變界面處的費米能級高度使外電路電荷定向移動形成的；對于應力為1KPa的機械振動,響應電流為10nA,振動探測相對誤差小于0.37%。外加工作電壓模式下,壓電勢對肖特基勢壘的調控和壓電阻效應的共同作用提升了響應電流。當工作電壓為+3V時,器件對應力為1KPa的機械振動的響應電流相對變化率提升到3700%,探測相對誤差小于0.91%,并成功應用于人體脈搏振動的探測。 采用Pt/AhO3/ZnO結構的MIS型肖特基結,研究了壓電電子效應對金屬/ZnO肖特基結的界面調控機理。采用原子層沉積方法在ZnO納米線表面制備的Al2O3絕緣層,有效降低了表面態(tài)對接觸勢壘的影響,阻止了光照下Pt表面熱電子躍遷對壓電電子效應界面調控作用的影響。通過研究壓應變下界面接觸勢壘、界面電阻和界面光生載流子的變化,發(fā)現隨著壓縮應變增加到-1.0%時,肖特基勢壘提高了147meV,界面載流子分離效率提升了2.7倍,界面電阻顯著提升。揭示了壓應變對ZnO金屬肖特基結的界面調控機制為：壓應變在界面處產生的負極化電場排斥空間電荷區(qū)載流子向ZnO內部的準平衡區(qū)移動,降低了空間電荷區(qū)的載流子濃度,展寬了空間電荷區(qū)的寬度,提高了內建電場強度,抬高了界面勢壘高度。
[Abstract]:Zinc Oxide (ZnO) nanomaterials have excellent semiconductor properties and piezoelectric properties. Piezoelectric nanoscale and piezoelectric devices constructed by the piezoelectric properties of ZnO nanomaterials have become a new direction in the research field of nano semiconductor devices. The construction of high performance piezoelectric electronic devices and the study of the regulation of the piezoelectric effect on the carrier behavior at the interface of the device have become a hot spot of research.
In this study, a variety of one-dimensional ZnO nanomaterials were synthesized by optimizing the growth process. A single indium doped Zinc Oxide (In-ZnO) nanoscale flexible strain sensor was constructed. The strain response mechanism of the device was analyzed by finite element simulation, and a ZnO nanowire array vibratory sensor was constructed. The self driving mode and external voltage mode were studied. The response mechanism of the type device has realized the detection of low frequency mechanical vibration signals and applied to the detection of human pulse vibration. The Pt/Al2O3/ZnO Schottky junction was constructed. The regulation of the interface resistance, the contact barrier and the interface photogenerated carrier were studied. The mechanism of the piezoelectric electron effect on the carrier interface was revealed.
In-ZnO nanoribbons were prepared by gas phase deposition. The width of the nanoribbons was about 1 mu m, the thickness was about 200nm, the length was more than 100 mu m, the growth direction was [2110], and the upper surface was (0001) polar surface. By the hydrothermal synthesis process, the high density ZnO nanowire array and the high density ZnO nanowire array film were prepared by the process of hydrothermal synthesis. The sodium hydroxide was used. The ZnO seed layer was grown on flexible substrates and the ZnO nanowire arrays were grown on flexible substrates by alternately coating with ethanol solution of zinc acetate.
The flexible piezoelectric electronic strain sensor is constructed by using In-ZnO nanometers. The static and dynamic strain detection is realized. The current voltage curve of the device is double Schottky rectifier. The current voltage curve moves up when the static strain is detected, and the tensile strain moves down. The finite element simulation is used to analyze the In-ZnO nanometers. Under the axial strain pressure potential distribution, it is found that under the effect of Poisson effect, the axial strain produces the piezoelectric potential on the surface of the In-ZnO nanometers on the polar surface, regulates the Schottky barrier height of the source drain and produces the strain response current. The periodic strain dynamic detection results show that the device has a clear and accurate response current and the strain time strain is compressed. The coefficient is 4036.
A Schottky type vibration detector is constructed with a flexible Pt electrode and a ZnO nanowire array. The device can detect the low frequency mechanical vibration signals in the self driving mode without the external working voltage and the external working voltage mode. The Fermi energy level makes the charge of the external circuit formed; for the mechanical vibration of the stress 1KPa, the response current is 10nA, the relative error of the vibration detection is less than 0.37%. and the working voltage mode, the joint action of the piezo potential to the Schottky barrier and the pressure resistance effect enhances the response current. When the working voltage is +3V, The relative change rate of the response current of the mechanical vibration of 1KPa is raised to 3700%, the relative error of the detection is less than 0.91%, and it is successfully applied to the detection of the pulse vibration of the human body.
Using the MIS type Schottky junction of Pt/AhO3/ZnO structure, the interface regulation mechanism of the piezoelectric electron effect on the metal /ZnO Schottky junction is studied. The Al2O3 insulating layer prepared on the surface of the ZnO nanowire by the atomic layer deposition method can effectively reduce the effect of the surface state on the contact barrier and prevent the piezoelectric electron effect from the thermal electron transition of the Pt surface to the piezoelectric electron effect. By studying the influence of interface control. By studying the interface contact barrier under the pressure strain, the interface resistance and the interfacial photogenerated carrier, it is found that the Schottky barrier is increased by 147meV with the compression strain increasing to -1.0%, the interfacial carrier separation efficiency is increased by 2.7 times and the interfacial electrical resistance is significantly improved. The pressure strain is revealed to the ZnO metal Schott. The interface regulation mechanism of the base junction is that the negative polarization electric field produced by the compressive strain at the interface rejects the shift of the space charge carrier into the quasi equilibrium region within the ZnO, reducing the carrier concentration in the space charge region, broadening the width of the space charge area, improving the strength of the internal electric field and raising the height of the interface barrier.
【學位授予單位】：北京科技大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：TN384;TB383.1

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本文編號：1990523