摘要：長久以來,將LED應用於微電子顯示幕一直是科學界及工業界非常感興趣的, 他的應用如戶外大型顯示(展出)幕, 人工眼角膜, 電子掃描及印刷顯示, 等等, 典型的戶外大面板顯示(展出)利用離散 3 - 顏色的領導此時有外部譯碼器電路(繞行)控制圖像信號。為了認識到(實現) 3 個顏色, 當(儘管)四進制 (例如 InGaAlP ) 為紅(色)的 (或者綠色) 噴射使半導體混合, 那些領導使用(用處)氮化物對於藍和綠色的光基礎(底模)了材料。 那麼遠為止, R , G , B 3 個顏色在氮化物材料上不能一起綜合因為 InGaN 銦的高集中很不穩定。 因此, 以離散顏色典型地虛構迷你顯示(展出), 它(這)佔領(佔有)了大空間和消耗重要數量的權力(動力)。
我們提出一個新奇的方法(以)(進行)徹底完整的 3 - 顏色的 大型電子展示 迷你顯示(展出)。 這個開始藝術方法結合氮化物- - 基礎(底模)了綠色 大型電子展示 , 氮化物基礎(底模)的藍領導和 磷光體 使紅(色) 大型電子展示 轉變成一個完整單元架構。 和所有三個顏色與一個標準的的和典型的半導體過程(方法)都分享這個相同
Abstract: Whitelight light emitting diodes (LEDs) have, recently, been regarded as the Holy Grail to replace fluorescent lamps for general illumination and backlight Cold Cathode Fluorescent Lamps (CCFLs) for flat panel displays. It is estimated that the cost of LEDs be reduced to 1/3 ~ 1/5 of current price for CCFL applications and 1/20 ~ 1/100 for general illuminations. Therefore, it becomes a serious subject for LED researchers to increase the LED efficiency at least 3 to 5 times more than current values. Moreover, LED arrays become a popular approach for higher power applications due to efficiency and economy purpose. The control circuits of the nitride based LED (microdisplay) array, so far, are all external. They are used to convert AC supply voltage to DC constant current and to protect LED devices from any potential power surge. This kind of external circuit itself is an extra component which is susceptible to damages. Also, it cannot adjust the variations of emitted optical power of each LED device caused by material growth and process variations. In addition to the above drawbacks, it’s also costly.
We propose a LED cell integrated with nitride based HFETs and high-efficient LEDs. Both HFET switches and LEDs share the same substrate (either SiC or Sapphire) on which the combined devices have the advantages of less power consumption on the conducting metal strips and higher power efficiency since only the selected pixel (channel) is on.
The first highlight of this proposal is to fabricate high-efficiency nitride based LEDs. We propose an isolation dopant zone that is able to enhance current spreading from p-type contact. Furthermore, we fabricate state-of-the art nitride based HFETs which perfectly fit the integration purpose for LED switches. The HFET switches and the combined capacitors, which serve the purpose of protecting LEDs and charge-pumps, are adjacent to the LED. In this way, the whole unit cell is less sensitive to process variations. In addition, since the capacitors of each unit cell are fabricated internally, instead of externally, the on-off response is more prompt.
The whole proposal is divided into mainly 4 parts. First, high efficiency LEDs and HFETs devices are fabricated. In the second part, optical and electronic characteristics of LEDs and HFETs are benchmarked. And then we design a unit cell to obtain the optimum response time and LED protection. Finally, we fabricate the integrated LEDs and HFETs and characterize the whole unit cell performance.