Formation of Hybrid Molecules Composed of Ga Metal Particle in Direct Contact with InGaAs Semiconductor Quantum Ring

We demonstrate the formation of hybrid molecules composed of a pair of a metal particle and a semiconductor quantum ring (QR) by using molecular beam epitaxy on a GaAs (100) surface. To form three-dimensional semiconductor InGaAs QRs with a hole in the center of the structure, a thin layer (10 monolayer) of GaAs was applied on InAs quantum dots, which transformed the distribution of surface free energy. These InGaAs QRs were then used as a template for the localization of Ga metal particles; there was one metal particle on a QR. By choosing the optimal surface temperature (most favorable thermal energy), the surface diffusion of Ga adatoms was effectively enhanced. This, in turn, allowed the localization of Ga metal particles on InGaAs QRs, consequently forming hybrid molecules. This study helps understand the formation of various types of hybrid molecules that will be used in applications in optoelectronics.