(Invited) Size Controlled Silicon Quantum Dots: A Model System for Understanding the Physics of Indirect Quantum Dots

Abstract

The fabrication of SiOx/SiO2 superlattices combined with thermal annealing enables the size and density control of Si quantum dots [1]. The layered-arranged Si nanocrystals represent a model system to systematically study the photonic and electronic properties of (indirect bandgap) quantum dots prepared in a CMOS compatible way. Hence, the size controlled nanocrystals are used to understand the interplay of absorption and recombination, the carrier kinetics and the electronic transport properties for matrix embedded Si quantum dots. Starting with the temperature dependence of the size depending band gap [2] we will discuss the interplay of radiative and non-radiative recombination for high quantum yield [3-5]. Doping of quantum dots and the respective experimental techniques for its quantification is at the very limit of the nowadays experimental possibilities. We will present systematic doping experiments with P and B which will be analyzed for doping efficiency, in-cooperation into the Si QDs and self-purification effects [6, 7]. [1] M. Zacharias et al. Appl. Phys. Lett. 80 (2002) 661. [2] A. M. Hartel et al. Phys. Rev. B 85, 165306 (2012). [3] A.M. Hartel et al. Rev. B 87, 035428 (2013). [4] J. Valenta et al J. Appl. Phys. 122 144303 (2017) [5] M. Greben et al. Beilstein J. Nanotechnol. 8, 2315 (2017). [6] D. Hiller et al. Scientific Reports 7, 863 (2017). [7] D. Hiller et al. Scientific Reports 7, 8337 (2017).