Synergic Integration of Conjugated Luminescent Polymers and Three-Dimensional Silicon Microstructures for the Effective Synthesis of Photoluminescent Light Source Arrays

In this work, a novel and straightforward technology for the fabrication of two-dimensional (2D) photoluminescent light source arrays by selective infiltration of conjugated luminescent polymers into three-dimensional (3D) silicon microstructures is presented. Poly(9,9-di-n-octylfluorene-alt-benzothiadiazole) (F8BT) integration into 3D silicon microstructures is investigated by means of three different deposition techniques, namely, spin-coating, dip-coating and drop-casting/ slow solvent evaporation. The microstructure is fabricated by electrochemical micromachining (ECM) technology and integrates 2D arrays of square holes with different sizes (about 40 and 4 μm), spatial periods (about 70 and 10 μm), and aspect ratios (ARs) (about one and ten). Notably, square holes with higher AR can be selectively filled with polymer using spin-coating and drop-casting techniques, whereas dip-coating technique allows selective polymer filling of square holes with lower AR. Independently of size, period and AR, each polymer-infiltrated hole behaves as a single light source, thus enabling the effective synthesis of 2D photoluminescent light source arrays.