| Abstract Scope |
Since the 1990s, self-assembled quantum dots (QDs) have been investigated for technologies from lasers to solar cells. Driven by compressive strain, III-V semiconductor QDs form spontaneously on (001) surfaces. However, for certain applications, QDs grown on non-(001) surfaces, or under tensile rather than compressive strain, are needed. The low fine-structure splitting of (111) QDs makes them ideal entangled photon sources. Tensile-strain QDs would have dramatically reduced band gaps and host light-hole excitons, with implications for IR optoelectronics and quantum transduction. However, until recently it has been difficult to synthesize non-(001) or tensile-strained QDs without crystallographic defects. I will introduce a QD self-assembly process that overcomes these difficulties. Using molecular beam epitaxy, we can reliably and controllably grow defect-free, tensile-strained QDs on (111) surfaces. I will discuss tensile-strained self-assembly in several material systems, and present data confirming the promise of these novel QDs for quantum information and IR photonic applications. |