可用于器件的侧墙GaAs量子线列阵结构

Useful Sidewall Quantum Wire Arrays

本文介绍了一种可以实用的侧墙式ＧａＡｓ量子线及其列阵结构．沿〔０１－１〕方向腐蚀条形的（３１１）Ａ衬底上，分子束外延生长的各向异性导致了侧墙量子线结构的形成．用光栅刻蚀方法，制备了横向周期为１μｍ、纵向三层叠加的三维侧墙量子线列阵．阴极荧光谱研究表明：在５Ｋ下，发光主要来自量子线区域，在两侧的量子阱区域只有很弱的发光峰；认为低温下载流子主要束缚在量子线区域，在量子阱区域也有少量载流子被外延层涨落产生的局域态所束缚．随温度升高到８５Ｋ以上直至室温下，只能观察到来自量子线区域的发光峰．这是由于束缚在量子阱局域态中的载流子大部分由于热激发而弛豫至量子线区域，参与量子线的发光．这种量子线列阵横向限制能量达到了２２０ｍｅＶ，表明该量子线列阵结构可以用于制备发光等实用器件．

Abstract Sidewall quantum wire (QWRs) structures and three dimensional arrays are introduced in this work. The sidewall QWRs were formed during molecular beam epitaxy (MBE) growth on GaAs (311)A substrates patterned with stripes along 01 1 directions due to selectivity of the growth. Three dimensional arrays of quantum wires structures were grown the GaAs (311)A substrates patterned with 500 nm pitch gratings. The cathodoluminescence (CL) spectra at 5K show that the dominated CL emission corresponds to the quantum wires and a very weak emission from the connecting quantum wells due to localization of excitons at random interface fluctuations. Only the strong emission from the quantum wires can be observed when the carriers in the quantum well become delocalized at higher temperature up from 85K to 300K, indicating perfect carrier capture into the quantum wires. Very high lateral confinement energy of 220 meV is achieved in this quantum wire arrays. Thus, device quality of this quantum wire structure is proved.