Size-Dependent Asymmetric Auger Interactions in Plasma-Produced n- and p-Type-Doped Silicon Nanocrystals

Abstract

Nonradiative Auger recombination (AR) tends to dominate carrier dynamics in charged, quantum-confined structures. Consequently, it complicates the practical realization of many semiconductor nanocrystal (NC)-based devices such as light-emitting diodes, photovoltaic cells, and single-photon emitters, in which charged exciton states often occur. To this end, extensive experimental studies on direct band gap NCs have investigated the trion components (both positive and negative) that construct the total AR rate. However, such an analysis has remained elusive for indirect band gap Si NCs. In this study, we investigate AR decay of non-thermal plasma-produced n- and p-type-doped Si NCs. We expand the study over a large NC size range (DNC ≈ 3–8 nm), in which n- and p-type doping is achieved by either a substitutional or surface doping effect, respectively. First, we monitor the AR of charge-neutral multiexcitons by measuring the biexciton lifetime (τXX) as a function of the NC size and doping configuration. We s...