GaN纳米柱的量子效率研究  

The quantum efficiency study of GaN nanorods

作　　者：李扬扬[1] 陈鹏[1,2] 蒋府龙 杨国锋[1] 刘斌[1] 谢自立[1] 修向前[1] 韩平[1] 赵红[1] 华雪梅[1] 施毅[1] 张荣[1] 郑有炓[1] 

机构地区：[1]南京大学电子科学与工程学院,江苏省光电功能材料重点实验室,南京210093 [2]南京大学扬州光电研究院,扬州225009

出　　处：《南京大学学报（自然科学版）》2014年第3期320-324,共5页Journal of Nanjing University（Natural Science）

基　　金：国家重点基础研究发展规划(2011CB301900);国家高技术研究发展规划(2009AA03A198);国家自然科学基金(61176063;60990311;60936004);江苏省自然科学基金(BK2008019;BK2010385;BK2009255;BK2010178)

摘　　要：主要通过低温和室温变功率光致发光(PL)谱的实验手段,研究了GaN纳米柱和对应薄膜(作为参考)的量子效率表现.实验中发现在室温,激发光功率为0.5mW时,GaN纳米柱的积分PL强度是薄膜的12.2倍,这表明GaN纳米柱具有比薄膜更高的内量子效率和光引出效率.另外,依据高低温积分PL强度比的方法计算得到激发光功率0.5mW时,GaN纳米柱的内量子效率低于薄膜,该计算结果违背由实验现象得到的结果,这表明该内量子效率的计算方法是不合适的,因而建立了一种新模型,得到GaN纳米柱和薄膜的内量子效率比随激发光功率的变化规律,结果表明GaN纳米柱的内量子效率表现显著优于薄膜.The purpose of the study is to compare the quantum efficiency performance of GaN nanorods and as-grown planar by excitation power dependent photoluminescence（PL）at the temperature of 6 and 300K.An enhancement of 12.2 times in the room temperature integrated PL intensity is observed from the GaN nanorods,in comparison to that of as-grown planar, with the excitation power of 0.5 mW.This large integrated PL intensity enhancement of GaN nanorods can be attributed to the improvement of internal quantum efficiency （IQE）as well as light extraction efficiency.However,the IQE of GaN nanorods is smaller than that of as-grown planar by using traditional method of calculating IQE,defined as IQE=IPL300K/IPL6K ,with the excitation power of 0.5 mW,which is opposite to the above experimental phenomena.It means that the traditional method is inappropriate.Therefore,a new model for calculating IQE is put forward.According to the new model, the ratio of IQE of GaN nanorods over that of as-grown planar as a function of excitation power at 6 and 300K can be＆amp;nbsp;achieved.The result turns out that the IQE performance of GaN nanorods is significantly better than that of as-grown planar,which is in agreement with the above experimental phenomena.

关 键 词：GaN纳米柱 光致发光(PL) 量子效率 

分 类 号：TN383[电子电信—物理电子学]