Enhanced electrical and luminescent performance of a porous silicon/MEH-PPV nanohybrid synthesized by anodization and repeated spin coating

Abstract

The electrochemical anodization of a single crystalline silicon in hydrofluoric acid-based solution leads to the formation of porous silicon (PSi) with tunable pore sizes and morphology for a wide range of technological applications. By infiltrating the as-anodized PSi layer with a conducting polymer, new functionalities can be achieved. Herein, we report on the enhancement of the electrical and luminescent properties of a nanohybrid composed of ∼100 nm PSi infiltrated by poly(2-methoxy-5-(2-ethylhexyloxy)-p-phenylenevinylene) (MEH-PPV) via a repeated spin coating technique. Morphological and structural investigations using FE-SEM and XRD on the hybrid nanostructure revealed a successful deposition of MEH-PPV inside the entire porous channels with a low degree of crystallinity. A partial silicon oxide formation was confirmed by FT-IR and XPS measurements. Furthermore, a remarkable increase in the electrical properties was detected by measuring the I–V curves and the electrochemical impedance spectroscopy (EIS). Moreover, a noticeable photoluminescence (PL) spectral enhancement after the MEH-PPV deposition into the PSi was detected. The spectral analyses for the current system indicate the possibility of exciton transfer from PSi to the MEH-PPV polymer. This simple synthetic approach can open new opportunities for the development of hybrid nanostructures of PSi and conducting polymers with potential for optical device applications.