Résumé
Disordered arrays of silicon nanowires have been produced by the OAG technique. The UV-visible absorption spectrum of the SiNWs shows a main increase of the absorption extending in the near infrared and similar absorption than bulk crystalline silicon below 400 run. T EMT simulation of the UV absorption of silicon nanowires predicts a main optical absorption for a nanowire orientation parallel to the electric field vector of the incident light, as expected for SiNW lying with a dominant orientation parallel to the substrate. The enhanced optical absorption tail extending above 400 run has been attributed to the combination of band gap opening shown by the PL emission and high densities of silicon surface states at high surface/volume ratio. Hybrid solar cells have been fabricated through the dispersion of silicon nanowires in a poly(3-hexylthiophene) thin film leading to a 1.14 % conversion yield, which was increased to 3.04 % upon SiNW surface functionaliz143ation, opening new perspectives for self sufficient power supplies applicable to remote sensing.