Room temperature single-electron memory and light sensor with three-dimensionally positioned InAs quantum dots

The authors report on the fabrication and characterization of single-electron memories based on site-controlled InAs quantum dots (QDs) embedded in a GaAs/AlGaAs quantum-wire transistor. By using a hole structure template on a modulation-doped GaAs/AlGaAs heterostructure in combination with etching techniques, two single InAs QDs were centrally positioned in a quantum-wire transistor so that pronounced shifts of the transistor threshold occur by charging of the QDs with single electrons. Single-electron read and write functionalities up to room temperature were observed. The memory function can be also controlled by light with a wavelength in the telecommunication range. (C) 2010 American Institute of Physics. [doi:10.1063/1.3520522]