Elaboration and characterization of Si(n)/PS/ZnO(n) structure obtained by rf-magnetron sputtering from aerogel nanopowder target material

Aluminum doped zinc oxide (AZO) thin film, generally used as TCO in solar cells, has been grown onto n-type porous silicon (PS) substrate by rf-magnetron sputtering at room temperature using aluminum (3 at%) doped nanocrystalline powder synthesized by the sol–gel method. The obtained AZO film with a thickness of about 0.4 μm was polycrystalline with an hexagonal wurtzite structure and preferentially orientated in the (0 0 2) crystallographic direction. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to study the film morphology. The obtained AZO film has a typical columnar structure and very smooth surface. From electric characterizations: current–voltage and capacitance–voltage (C–V) at different frequency measurements, we can conclude that we have a Schottky electronic behaviors where the depletion-layer is developed principally in the PS region of the PS/ZnO(n) heterojunction. The I(V) characterizations in dark and under illumination were also investigated.