Role of nanowire length in morphological and electrical properties of silicon nanonets

While electronic devices based on a unique nanowire are intensively studied, we present here the potential of random assemblies of silicon nanowires (SiNWs) as interesting material for electronic applications. This structure, called a nanonet (for NANOstructured NETwork), exploits the unique properties of the nanowires such as high surface area and large aspect ratio while avoiding the long, expensive and complex processing required for individual nanowire devices. In this work, the vacuum filtration method is used to elaborate homogeneous, reproducible and conducting silicon nanonets. A study of the morphological and electrical behavior of such nanonets is provided as a function of the SiNW length and density. We demonstrate that despite the complexity of the nanonet geometry, it is possible to control their morphology and their electrical properties. Besides, we show that these characteristics strongly depend on the SiNW length and density. In view of the obtained properties, we demonstrate that Si nanonets are electrically active materials with interesting morphological properties and a potential for a wide range of applications and particularly in the sensing field.