發(fā)布時(shí)間：2018-01-03 18:38

  本文關(guān)鍵詞：GaN基隧穿器件的制備及特性的研究　出處：《吉林大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： MOCVD p-Ga N PITJ p-Ga N/n-Zn O

【摘要】：目前,Ga N基LED已經(jīng)進(jìn)入到了市場(chǎng)化發(fā)展階段,但是其在許多方面還存在著不足,如:(1)Ga N的p型載流子濃度相對(duì)較低、且電極的接觸電阻較大;(2)量子阱(MQWs)中存在量子限制斯塔克效應(yīng),使得電子/空穴對(duì)的復(fù)合幾率變小;(3)高In組分的In Ga N生長(zhǎng)困難,且缺陷很多,從而降低了Ga N基LED的發(fā)光效率。近年來,國(guó)際上很多課題組開展了利用極化誘導(dǎo)隧穿結(jié)(PITJ:polarization-induced tunneling junction)提高Ga N基LED發(fā)光效率的研究工作。在Ga N基LED中引入PITJ具有如下優(yōu)點(diǎn):(1)隧穿作用可以增加器件的空穴注入;(2)n-Ga N的橫向擴(kuò)展電阻要低于p-Ga N,以n-Ga N代替p-Ga N作為橫向電流傳輸層,可以減小串聯(lián)電阻,提高擴(kuò)展電流;(3)n-Ga N電極的接觸電阻要小于p-Ga N,以n-Ga N代替p-Ga N作為電極的歐姆接觸層,可以避免p-Ga N歐姆接觸產(chǎn)生的吸收損耗,從而提高Ga N基LED的發(fā)光特性。本論文根據(jù)Ⅲ族氮化物的極化和隧穿理論,開展了Ga N基隧穿器件的制備及特性研究。具體的研究?jī)?nèi)容如下:1.利用MOCVD技術(shù),開展了高質(zhì)量Mg摻雜p-Ga N薄膜的研究與制備工作。主要研究了p-Ga N薄膜的生長(zhǎng)溫度、Mg源流量和退火溫度對(duì)其晶體質(zhì)量、載流子濃度及電阻率的影響。通過優(yōu)化生長(zhǎng)參量,我們制備了高質(zhì)量的p-Ga N薄膜。在生長(zhǎng)溫度為985℃、Mg源流量為250sccm、退火溫度為900℃時(shí),p-Ga N薄膜的(0002)晶面XRD搖擺曲線半峰寬(FWHM)僅為~250arcsec,空穴濃度可以達(dá)到5.2×10~17/cm~3。2.基于極化理論和隧穿理論,開展了極化誘導(dǎo)隧穿結(jié)的研究與制備工作。主要研究了Al Ga N極化層的厚度和組分對(duì)PITJ結(jié)構(gòu)特性和電學(xué)性質(zhì)的影響。通過優(yōu)化生長(zhǎng)參量,我們制備了具有反向整流特性的p-Ga N/Al Ga N/n~+-Ga N極化誘導(dǎo)隧穿結(jié)。在Al Ga N極化層厚度為10nm、組分為0.1時(shí),PITJ的電學(xué)性質(zhì)最佳。此時(shí),在5V的反向電壓下,可以獲得8.57m A的反向隧穿電流。3.制備了PITJ p-Ga N/n-Zn O異質(zhì)結(jié)LED和p-Ga N/n-Zn O異質(zhì)結(jié)LED,深入研究了極化效應(yīng)和隧穿效應(yīng)對(duì)p-Ga N/n-Zn O異質(zhì)結(jié)LED光電特性的影響。相較于p-Ga N/n-Zn O異質(zhì)結(jié)LED,PITJ p-Ga N/n-Zn O異質(zhì)結(jié)LED表現(xiàn)出更高的發(fā)光強(qiáng)度和更好的發(fā)光穩(wěn)定性。在20m A電流下,帶有PITJ結(jié)構(gòu)的p-Ga N/n-Zn O異質(zhì)結(jié)LED的發(fā)光強(qiáng)度是普通p-Ga N/n-Zn O異質(zhì)結(jié)LED的1.4倍;連續(xù)工作8h后,PITJ p-Ga N/n-Zn O異質(zhì)結(jié)LED的發(fā)光強(qiáng)度只減弱3.5%。
[Abstract]:At present, Ga-N-based LED has entered the stage of market-oriented development, but it still has some shortcomings in many aspects, such as the relatively low concentration of p-type carriers at 1: 1 Ga-N. The contact resistance of the electrode is larger; (2) the existence of quantum confinement Stark effect in quantum well MQWs makes the recombination probability of electron / hole pairs smaller; (3) the in Ga N with high in composition is difficult to grow and has many defects, which reduces the luminescence efficiency of Ga N based LED in recent years. Many international research groups have developed polar-induced tunneling junction (PITJ: polarization-induced tunneling junctions). In order to improve the luminescence efficiency of gan based LED, the introduction of PITJ into gan based LED has the following advantages: 1) tunneling can increase the hole injection. The transverse spread resistance of n-Ga N is lower than that of p-Ga N. The series resistance can be reduced and the spreading current can be increased by using n-Ga N instead of p-Ga N as the transverse current transport layer. The contact resistance of n-Ga N electrode is smaller than that of p-Ga N electrode, and the ohmic contact layer of p-Ga N electrode is replaced by n-Ga N electrode. The absorption loss caused by p-Ga N ohmic contact can be avoided and the luminescence characteristics of Ga N based LED can be improved. The fabrication and characteristics of gan based tunneling devices are studied. The specific research contents are as follows: 1. Using MOCVD technology. The research and preparation of high quality mg doped p-Ga N thin films were carried out. The growth temperature, mg source flux and annealing temperature of p-Ga N thin films on their crystal quality were studied. By optimizing the growth parameters, high quality p-Ga N thin films were prepared, and the flux of mg source was 250 SCcm at 985 鈩，

本文編號(hào)：1375118