Charge Tunable GaAs Quantum Dots in a Photonic n-i-p Diode

In this submission, we discuss the growth of charge-controllable GaAs quantum dots embedded in an n-i-p diode structure, from the perspective of a molecular beam epitaxy grower. The QDs show no blinking and narrow linewidths. We show that the parameters used led to a bimodal growth mode of QDs resulting from low arsenic surface coverage. We identify one of the modes as that showing good properties found in previous work. As the morphology of the fabricated QDs does not hint at outstanding properties, we attribute the good performance of this sample to the low impurity levels in the matrix material and the ability of n- and p-doped contact regions to stabilize the charge state. We present the challenges met in characterizing the sample with ensemble photoluminescence spectroscopy caused by the photonic structure used. We show two straightforward methods to overcome this hurdle and gain insight into QD emission properties.

Automated summary

This study discusses the growth and characteristics of charge-controllable GaAs quantum dots in an n-i-p diode structure, revealing a bimodal growth mode and identifying a mode with good properties. The good performance of the sample is attributed to low impurity levels in the matrix material and the ability of contact regions to stabilize the charge state. Challenges in characterizing the sample were addressed with two straightforward methods to gain insight into QD emission properties.