p型氧化鋅奈米線之合成、鑑定和應用研究

Synthesis, Characterization, and Applications of p-Type ZnO Nanowires

陳敏騰(Min-Teng Chen)

指導教授 ： 陳力俊

國立清華大學/工學院/材料科學工程學系/博士(2010年)

https://doi.org/10.6843/NTHU.2010.00599

摘要

Abstract

Among semiconductor materials, zinc oxide is one of the most important materials and has attracted much interest in recent years, due to its unique optical, electrical, magnetic and piezoelectric properties and versatile applications. Fabrication of n-type, p-type and p-n homojunction ZnO nanowires (NWs) was developed by using a vapor transport and condensation method without Au as catalyst. ZnO-coated Si wafer was used as a substrate for the growth of n-type, p-type and p-n homojunction ZnO nanowires. For p-type ZnO nanowires, the phosphorus-doped ZnO nanowires were grown on ZnO-coated substrate using zinc phosphide (Zn3P2) as the dopant source. Single-crystal intrinsic ZnO and P-doped ZnO nanowires have the growth axis along the [001] direction and are vertically-aligned on Si substrates. Furthermore, single-NW-based field-effect transistors (FETs) were used to study the electrical transport properties of the ZnO NWs.
Using phosphorus doped ZnO nanowire arrays grown on silicon substrate, energy conversion using the p-type ZnO NWs has been demonstrated for the first time. The p-type ZnO NWs produce positive piezoelectric output voltage pulses when scanned by a conductive AFM in contact mode. The output voltage peaks are as high as 50-90 mV for NWs with ~150 nm in diameter and 3-4 μm in length. The output voltage pulse is generated when the tip contacts the stretched side (positive piezoelectric potential side) of the NW. In contrast, the n-type ZnO NW produces negative piezoelectric output voltage when subjected to AFM deformation. On the other hand, the output voltage pulse is generated when the tip contacts the compressed side (negative potential side) of the NW. These experimentally observed phenomena have been systematically explained based on the mechanism proposed for nanogenerator.
Catalyst-free p-n homojunction ZnO nanowire (NW) arrays, in which the phosphorous (P) and zinc (Zn) served as p- and n-type dopants, respectively, have been synthesized for the first time by a controlled in-situ doping process for fabricating efficient ultraviolet light emitting devices. The doping transition region defined as the width for P atoms gradually occupying Zn sites along the growth direction can be narrowed down to sub-50 nm. The cathodoluminescence emission peak at 340 nm emitted from n-type ZnO:Zn NW arrays is likely due to the Burstein-Moss effect in the high electron carrier concentration regime. Further, the electroluminescence spectra from the p-n ZnO NW arrays distinctively exhibit the short-wavelength emission at 342 nm and the blue-shift from 342 nm to 325 nm is observed as the operating voltage further increasing. The ZnO NW p-n homojunctions comprising p-type segment with high electron concentration are promising building blocks for short-wavelength lighting device and photoelectronics.

摘要

氧化鋅由於具備獨特的光、電、磁以及壓電特性並且具有廣泛的應用性,因此是所有半導體材料中備受矚目的材料之一，因而在近幾年吸引了相當廣泛的研究。由於不同型態、維度及尺寸的氧化鋅具有其不同的性質及應用面，所以如何設計及控制氧化鋅奈米結構的成長便成了研究學者們的重點。n型、p型以及p-n同質接面氧化鋅奈米線是經由氣相沉積的方式來製備，其中成長過程不需藉由金當作催化劑。n型、p型以及p-n同質接面氧化鋅奈米線於已沈積氧化鋅作為核種之矽基板上成長。對於p型氧化鋅奈米線的製備，是以磷化鋅作為摻雜物並均勻的摻雜到氧化鋅奈米線內。合成出來的本質性氧化鋅及磷摻雜氧化鋅為單晶結構且均直立於矽基板上並沿著[001]方向成長。此外，藉由量測單根奈米線之場效應電晶體，進一步探討所合成之奈米線的電傳導性質。
利用成長於矽基材上之磷摻雜氧化鋅奈米線,第一次證實此p型氧化鋅奈米線能夠產生能量轉換效應。藉由一個導電性的AFM探針以接觸模式來掃掠p型氧化鋅奈米線，並且產生正向壓電輸出電壓脈衝。對於一片長滿直徑為150 nm且長度為3-4 μm之奈米線所產生的輸出電壓高達50-90 mV。當AFM探針接觸奈米線的伸展面時(正向壓電電位面)，就會產生正電壓輸出脈衝。相對的，當n型氧化鋅奈米線經由AFM探針接觸而產生變形時，會產生負向壓電輸出電壓；此電壓輸出脈衝是由於探針觸接奈米線的壓縮面(負向壓電電位面)所產生的。這些實驗上所觀察到的現象可依據奈米發電機相關而加以解釋。
p-n均質接面的氧化鋅奈米線陣列分別以磷(P)及鋅(Zn)作為p型及n型摻雜物、不需藉由催化劑並且第一次成功地藉由可控制同步摻雜過程來合成，並且製備成紫外光LED元件。摻雜的過渡區域被定義為磷原子沿著奈米線的成長方向逐漸地佔據鋅原子位置之寬度，其中此過渡區域的寬度可以縮小至50 nm以內。從n型ZnO: Zn奈米線陣列中所放出340 nm的CL放射光，可能是在高電子載子濃度區域內由於Burstein-Moss效應而所放出來的光。此外，從p-n氧化鋅奈米線陣列所量測到的EL光譜圖明顯地顯示在342 nm附近接收到一個短波長放光，隨著操作電壓的增加，此放光波長明顯地會從342 nm藍位移到325 nm。合成一個包含高電子濃度之p型線段所構成的氧化鋅奈米線p-n均質接面結構有潛力應用於發展短波長發光元件及光電領域的應用。

關鍵字

p型 ； 氧化鋅 ； 奈米線 ； 壓電 ； 發光二極體 ； p-n homojunction

並列摘要

無資料

並列關鍵字

p-type ； ZnO ； nanowire ； piezoelectric ； LED ； p-n均質接面

參考文獻

1.60 G. D. Yuan, W. J. Zhang, J. S. Jie, X. Fan, J. A. Zapien, Y. H. Leung, L. B. Luo, P. F. Wang, C. S. Lee, S. T. Lee, “ p-Type ZnO Nanowire Arrays” Nano Lett. 2008, 8, 2591.

5.4 Lin, S. S.; Hong, J. I.; Song, J. H.; Zhu, Y.; He, H. P.; Xu, Z.; Wei, Y. G.; Ding, Y.; Snyder, R. L.; Wang, Z. L. “Phosphorus doped Zn1-xMgxO nanowire arrays” Nano. Lett. 2009, 9, 3877.

Chapter 1

1.3 Hah, J. H.; Mayya, S.; Hata, M.; Jang, Y. K.; Kim, H. W.; Ryoo, M.; Woo, S. G.; Cho, H. K.; Moon, J. T., “Converging lithography by combination of electrostatic layerby layer self-assembly and 193 nm photolithography: top-down meets botton-up,” J. Vac. Sci. Technol. B. 2006, 24, 2209-2213.

1.4 Alivisatos, P., “Semiconductor clusters, nanocrystals and quantum dots,” Science 1999, 271, 933-934.