This project is to investigate an efficient modelling, fabrication and characterisation technique to realise a multifunctional integrated nanosystems for nanoelectronic and nanophotonic applications. A rigorous numerical modelling approach based on finite difference time domain method will be explored to simulate the semiconductor nanowire structures. Different semiconductor material (e.g. silicon and zinc oxide) will be investigated and assesed for its suitability for light guiding, absorption and non-linear effect for potential slow light application in optical communication and quantum opticical switching. The nanowire structure will be fabricated using bottom-up approach under different growth conditions to achieve the optimum structural and geometrical features. The photonic and electrical nanowire characterisation will be based on near field optical microscopy, broadband laser spectroscopy and dc semiconductor parametric analyser.