以PIC法模擬場發射電子流之研究

Abstract

場發射顯示器是一種新式平面顯示器，自從奈米碳管被發現以後，它就變的大有可為。場發射顯示技術和一般的陰極射線管電視類似，都是利用電子撞擊螢光粒子引發可見光。在這篇論文裡，利用三維PIC法模擬傳統Spindt型場發射器和奈米碳管場發射器，研究不同的結構和不同的施加電壓所造成的影響。從模擬結果我們可以看出場發射機制確實有遵守Fowler-Norheim規則，奈米碳管和矽基場發射器之間的差異，主要是奈米碳管其高深寬比的幾何形狀所導致較大表面電場會噴出較大的電流。另外，結構裡多了聚焦電極後，電子流發散現象可以有效的改善，在有考慮空間電荷效應，聚焦極施加0伏特，電子散佈在陽極板的寬度將在 範圍內，且絕大多數在 以內。比較有考慮空間電荷效應和沒有考慮空間電荷效應的結果後，可以很明顯地看出場發射電流的差異，其原因是有考慮空間電荷效應時，在某一範圍距離內，電子電荷會影響場發射器局部表面電場大小甚鉅。

Field emission display is a new type flat-panel display. As carbon nanotubes were discovered, it became the most promising display. FED technology is similar in operation to CRTs in that phosphor is excited by a stream of electrons. In this study, we simulate the traditional Spindt type emitters and nanocarbon emitters by using 3D PIC method to comprehend the influences of structure, and applied field strength on emission current. CNT emitter has larger emission current than silicon-based emitter due to its high aspect ratio geometry. The results show that emission mechanism follows the Fowler-Norheim law. And in focus electrode applied 0 V with space charge effect case, electron dispersion width at anode could decrease effectively within the range of , and majority is within . However, it is obviously to see the difference of emission current with/without considering space charge effect, because space charge will influence local surface electric field within a certain distance.