Optical and photo-thermal investigations of MEH-PPV layer spin coated on nano-porous silicon structure

The optical and photothermal properties of porous silicon (PS) coated by Poly[2-methoxy-5-(2’-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV) polymer have been investigated. The PS layers were formed using electrochemical anodisation method. The deposition of the MEH-PPV polymer on PS and Si surfaces was performed by spin coating process. The MEH-PPV/Si, MEH-PPV/PS, and PS as well as MEH-PPV solution were prepared and compared by photoluminescence (PL) spectroscopy at room temperature. An enhancement of the PL intensity of PS was observed after the deposition of MEH-PPV molecules on its surface. Comparing it with a smooth Si surface, the porous surface plays an important role for the fixation of MEH-PPV molecules thus affecting the PL and the Photo-thermal properties of these structures. The thermal conductivity of MEH-PPV/PS is also increased compared to those of PS and MEH-PPV/Si. The values of the thermal conductivity of MEH-PPV/Si, PS, and MEH-PPV/PS were 0.69, 0.94, and 1.32 W.m^− 1.K^− 1, respectively. The optical and opto-thermal properties are related to the distribution of MEH-PPV molecules which in turn depends on the nature of the substrate surface.