In原子掺入对GaInNAs/GaAs单量子阱光致发光的影响

Influence of In Atoms Incorporation on the Luminescence of GaInNAs/GaAs Single Quantum Well

研究了In掺入GaNAs/GaAs单量子阱对其带间和低于带边发光性质的影响。实验结果显示 ,随着In浓度的增加 ,GaInNAs/GaAs量子阱带间发光得到改善 ,低于带边的发光强度大大地减小。这是由于GaIn NAs合金生长在GaAs衬底上 ,为补偿In和N原子尺度的差异 ,N原子更倾向于与In原子形成共价健。GaInNAs/GaAs单量子阱的光调制光谱证实了高能端发光峰来自本征的带边发光。

GaInNAs alloy has recently attracted considerable attention for both fundamental physical properties and its possible optoelectronic application in long wavelength optoelectronic devices based on GaAs.In general ,the interband luminescence efficiency would be decreased when N atoms are incorporated to form GaNAs and GaInNAs alloys,partly due to a large miscibility gap and phase separation of GaN and GaAs,or the formation of N clusters.It is well known that the incorporation of both In and N will reduce the energy gap of the alloy.Their band shrinkage effect is additive.Therefore,in order to obtain the high quality alloy material and to improve the interband luminescence efficiency in the 1 3 and 1 55μm wavelength region,the study of optimal condition for incorporating N and In atoms into GaInAs/GaAs quantum wells becomes important.In this paper,both GaInNAs/GaAs and reference GaInAs/GaAs quantum wells investigated here were grown on the same (001) GaAs substrate by plasma assisted molecular beam epitaxy.The optical properties of interband transitions and below the band edge have been investigated by incorporating In atoms into GaNAs/GaAs single quantum well.The experimental results show that with increasing In concentration the interband luminescence is improved and the photoluminescence intensity below the band edge in GaInNAs/GaAs single quantum well decreases significantly.An interpretation is given that N atoms are more preferable to form covalent bond with In than with Ga atoms in GaInNAs alloy due to the compensation of the atomic size difference between In and N atoms on GaAs substrate.Thus the lattice mismatched GaInNAs with more In atoms and less N atoms is perhaps a better choice than the lattice matched GaInNAs for luminescence devices.The photoreflectance spectra of the GaInNAs/GaAs single quantum well support to the assignment of the intrinsic mechanism of the high energy luminescence peak.