Tailoring the Charge Transport Properties of Printable Si‐NCs By Conjugated Organic Ligands

Abstract

Silicon is dominating the world in photovoltaic technology. The widely used mono crystalline and poly crystalline wafer technologies are expensive to process. As an alternative, technology of silicon nanocrystals (Si‐NCs) is a necessity for economical processing of PV modules. In this work, commercially prepared Si‐NCs with a mean diameter of 60 nm is utilized with a pre‐treatment process followed by functionalization. Styryl and 1‐ethenyl‐4‐fluoro benzyl conjugate moieties are grafted on hydrogen‐terminated Si‐NCs via hydrosilylation of phenylacetylene and 1‐ethynyl‐4‐fluoro benzene, respectively. Thick‐films of these functionalized Si‐NCs with different thicknesses are prepared and analyzed in a purposed device architecture at room temperature which reveals a p‐type character of functionalized Si‐NCs films. Detail analysis of current density–voltage (J–V) characteristics of styryl functionalized Si‐NCs films shows that the drifting of charge carriers follows a power law relationship (J ≈ Vn) in the presence of exponentially distributed trap states. Moreover, a unique voltage dependence of the J–V curves also reveals a transition between direct and Fowler–Nordheim (F–N) tunneling mechanisms.