White light emitting silicon nano-crystals-polymeric hybrid films prepared by single batch solution based method

Publication date: Available online 9 February 2016
Source:Thin Solid Films
Author(s): Mustafa H. Balci, Lars Martin Sandvik Aas, Morten Kildemo, Ragnhild Sæterli, Randi Holmestad, Mikael Lindgren, Tor Grande, Mari-Ann Einarsrud
Silicon nano-crystals have been studied intensively due to their photoluminescence properties and possible applications in new generation opto-electronic devices. Their importance in lightning and display technologies is increasing due to the abundance and non-toxicity of silicon. Here we report a single batch solution based synthesis route to silicon nano-crystal organic hybrid films exhibiting white light photoluminescence at room temperature upon excitation by ultraviolet light. Films prepared by ethylene glycol terminated Si nano-crystals showed maximum 240nm red shift in photoluminescence response upon excitation at 350nm. The shift was found to decrease in order for hybrid films fabricated using acrylic acid, 1-octanol acid and oleic acid terminated Si nano-crystals. The mean size of the Si nano-crystals (~2–10nm) estimated by Raman spectroscopy were smallest for the ethylene glycol capped Si nano-crystal films. The calculated Tauc bandgaps of the hybrid films varied between 1.51 and 2.35eV.