氮化銦奈米線的成長及其光學特性

Abstract

一維奈米結構如奈米線、奈米帶因為他獨特的光性、電性和機械性質而引發廣泛的興趣和研究。一維奈米材料特殊的結構性質可以有效率地提升傳輸電性載子的性能，而且這些一維結構非常適合在奈米積體電路上傳輸載子。再者一維奈米結構也具備元件的功能，所以這種一維奈米結構可以在奈米積體電路中當做接線和元件的應用。 氮化銦材料擁有0.7電子伏特的直接能隙，被預期能運用在高頻高速的元件和光通訊的材料上。本實驗利用低壓且以電阻式加熱板加熱的MOCVD，成功地在Si基板上成長各種不同形貌結構的氮化銦奈米材料。利用X光繞射譜線、拉曼光譜及高解像能穿透式電子顯微鏡可測定出所成長之氮化銦奈米尖錐為高度方向性的單晶奈米結構。本研究中，並以電子顯微鏡觀測試片表面。另外，利用紅外線的光激發螢光光譜系統在15K測量時，得到一個主要peak在0.77eV，和另一個peak在0.75eV，這兩個peak有20meV的間隔。再做變溫的光激發螢光光譜指出這20meV是InN nanowires的deep donor level。再表面處理之後，複合機率提高。並且可以看到螢光光譜的強度增強。這些增加的量子產量是由於減少表面的能階並且band-band的放光並沒有改變。

One-dimensional nanostructures, such as nanowires and nanobelts, have attracted great attention because of their peculiar optical, electrical and mechanical properties. 1D nanostructures illustrate the smallest dimension structure that can be efficiently transport electrical carriers, and thus are ideally suited to the critical and ubiquitous task of moving charges in integrated nanoscaled system. Second, 1D nanostructures can also exhibit device function, and thus can be exploited as both the wiring and device elements in architectures for functional nanosystems. Indium nitride (InN), with its wurtzite crystal structure and 0.7 eV direct band gap, is a promising III-V compound semiconductor for high-frequency and high-speed devices and optical communication. In this study, indium nitride various kinds of nanostructures were successfully grown on Si substrate using a simple resistive heated MOCVD system by utilizing a pyrolytic boron nitride heater. Structure studied by x-ray diffraction (XRD) spectra and Raman spectrometer and high resolution electron microscope (HRTEM) measurement revealed that single crystalline of indium nitride (InN) nanostructure. The scanning electron microscope (SEM) investigations on the indium nitride (InN) nanostructure show a surface morphology .On the other hand, using the infrared ray photo-luminescence (IR-PL) measurement system, when the PL spectrum at 15 K showed a main emission peak at 0.77 eV and another peak at 0.75 eV, with a 20 meV interval. Temperature-dependent PL measurements indicated a 20 meV-deep donor level in the InN nanowires. After surface modification, the recombination rates are increased. And for PL spectra, we also can see the enhancement of intensities. And Increased the quantum yield require the elimination of midgap surface states, and the band edge emission appear unaltered.