Influence of substrate misorientation on the photoluminescence and structural properties of InGaAs/GaAsP multiple quantum wells

Abstract

InGaAs/GaAsP multiple quantum wells (MQWs) were grown by metal-organic chemical vapor deposition on vicinal GaAs (001) substrates with different miscut angles of 0°, 2° and 15° towards [110]. The crystal structures of InGaAs/GaAsP were characterized by high-resolution X-ray diffraction and Raman spectroscopy. The surface morphologies of InGaAs/GaAsP MQWs were observed by atomic force microscopy. The mechanisms for step flow, step bunching and pyramid growth on 0°, 2° and 15° misoriented substrates were discussed. The results provide a comprehensive phenomenological understanding of the self-ordering mechanism of vicinal GaAs substrates, which could be harnessed for designing the quantum optical properties of low-dimensional systems. From low-temperature photoluminescence, it was observed that the luminescence from the MQWs grown on a vicinal surface exhibits a red-shift with respect to the 0° case. An extra emission was observed from the 2° and 15° off samples, indicating the characteristics of quantum wire and pyramidal self-controlled quantum-dot systems, respectively. Its absence from the PL spectrum on 0° surfaces indicates that indium segregation is modified on the surfaces. The relationship between InGaAs/GaAsP MQWs grown on vicinal substrates and their optical and structural properties was explained, which provides a technological basis for obtaining different self-controlled nanostructures.

Light Emitting Devices Based on Quantum Well-Dots

“…The large-sized QDs are formed only on the misoriented surface, cover many atomic steps, and likely appear due to coalescence of individual QWDs. The impact of surface misorientation angle was also studied in [18]. InGaAs/GaAsP multiple quantum wells (MQWs) were grown by MOVPE on vicinal GaAs (001) substrates with different miscut angles of 0°, 2°, and 15° towards [110].…”

“…The large-sized QDs are formed only on the misoriented surface, cover many atomic steps, and likely appear due to coalescence of individual QWDs. The impact of surface misorientation angle was also studied in [18]. InGaAs/GaAsP multiple quantum wells (MQWs) were grown by MOVPE on vicinal GaAs (001) substrates with different miscut angles of 0 Since the growth of QWDs is accompanied by a partial relaxation of elastic strain, there is no fast strain accumulation upon the stacking of QWD layers, and misfit dislocation formation is suppressed.…”

“…A number of research groups have investigated nanostructures that can be considered as intermediate cases between QWs and QDs. These structures were referred to as modulated quantum wells [16,17], as quantum wires [18][19][20][21][22][23][24], as 'Wires-on-Well' (WoW) [25,26], and as 'Well-Island' [27]. One approach is to use a dense array of small-sized QDs [21,28,29].…”

Влияние разориентации подложки на состав, структурные и фотолюминесцентные свойства эпитаксиальных слоев, выращенных на GaAs(100)

“…Одним из подходов, широко используемых при произ-водстве оптоэлектронных компонент и активно развива-емых в последнее время, является рост на подложках с разориентацией [6][7][8].…”

“…• , и в гетеростуктурах с квантовыми ямами [7], выращенных на подложках GaAs(100) с высоким отклонением от направления [110], использование разориентированных подложек позволи-ло эффективно управлять морфологией поверхности и оптическими характеристиками образцов.…”