Miniband formation engineering in GaN/AlN constant total effective radius multi-shells quantum dots and rings with on-center hydrogenic donor impurities

Abstract

In this work, we have studied the miniband and minigaps of GaN/AlN constant total effective radius multi-shells quantum dots (CTER-MSQDs) and Rings (CTERMSQRs).<br />We have investigated effects of the Hydrogenic donor impurities, quantum dots and rings radii, and the number of wells on miniband formation by sub-band energy calculations. We show that in these systems, minigaps can be created and then disappeared when the number of wells increases. We observe that cylindrical CTER-MSQDs have one miniband more than the spherical CTER-MSQD. However, minibands of the cylindrical CTER-MSQD are wider. For cylindrical systems, the first minigap position can undertake a blue shift but for spherical systems, we can not observe this fact. The first minigap position undertakes more<br />blue shifts when the inner QD radius R1 increases. Thus, the number of wells, Hydrogenic donor impurities, and quantum dot & ring radii can be used as tuning tools to have a system with the typical number of minibands and minigaps with desired widths.