The Fabrication of Nanoimprinted P3HT Nanograting by Patterned ETFE Mold at Room Temperature and Its Application for Solar Cell

Abstract

Nanoimprinting lithography (NIL) is investigated as a promising method to define nanostructure; however, finding a practical method to achieve large area patterning of conjugated polymer remains a challenge. We demonstrate here that a simple and cost-effective technique is proposed to fabricate the nanoimprinted P3HT nanograting by solvent-assisted room temperature NIL (SART-NIL) method with patterned ETFE film as mold. The patterned ETFE template is produced by embossing ETFE film into a patterned silicon master and is used as template to transfer nanogratings during the SART-NIL process. It indicates that highly reproducible and well-controlled P3HT nanograting film is obtained successfully with feature size of nanogratings ranging from 130 to 700 nm, due to the flexibility, stiffness, and low surface energy of ETFE mold. Moreover, the SART-NIL method using ETFE mold is able to fabricate nanogratings but not to induce the change of molecular orientation within conjugated polymer. The conducting ability of P3HT nanograting in the vertical direction is also not damaged after patterning. Finally, we further apply P3HT nanograting for the fabrication of active layer of OBHJ solar cell device, to investigate the morphology role presented by ETFE mold in device performance. The device performance of OBHJ solar cell is preferential to that of PBHJ device obviously.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-016-1481-y) contains supplementary material, which is available to authorized users.

Vapor-assisted room temperature nanoimprinting-induced molecular alignment in patterned poly(3-hexylthiophene) nanogratings and its stability during thermal annealing

“…It was reported that the NIL technique was not only able to fabricate the nanostructures but also to induce transition of the molecular and crystallographic ordering of imprinted materials which were able to self-organize. [30][31][32][33][34][35][36] In order to probe the effect of the VART-NIL procedure on the molecular alignment of P3HT polymer molecule, GIWAXD measurements of the polymer P3HT lm before and aer patterning were performed, with the corresponding results shown in Fig. 3 and 4.…”

“…Here, we also adopted the standard crystallographic notation for the P3HT polymer, where the (h00) plane, (010) plane and (001) plane are referred to as the layering direction, p-p direction and backbone direction, respectively. [30][31][32][33][34][35][36] Fig. S3 in the ESI † shows two typical edge-on and face-on molecule alignments of P3HT molecule chains on the substrate surface, and the lattice parameters a, b and c are distances between the backbones, p-p stacking distance and distance between the side chains, respectively.…”

“…S3 in the ESI † shows two typical edge-on and face-on molecule alignments of P3HT molecule chains on the substrate surface, and the lattice parameters a, b and c are distances between the backbones, p-p stacking distance and distance between the side chains, respectively. The diffraction vectors q xy and q z refer to the diffraction information parallel and vertical to the substrate surface, while the diffraction peaks at q ¼ 3.8 nm À1 and q ¼ 16.8 nm À1 correspond to the (100) plane and (010) plane reection signals of the P3HT crystal, [32][33][34][35][36] respectively. Fig.…”

“…In our previous study, we developed a simple and cost-effective solvent-assisted room-temperature NIL (SART-NIL) method based on the NIL technique. [33][34][35][36] SART-NIL technical was employed not only to fabricate the poly(3-hexylthiophene) (P3HT) nanostructures but also to prepare the desired morphology in the active layer of ordered bulk heterojunction photovoltaic cells based on uniform P3HT nanostructures surrounded by PCBM material. We also found that the SART-NIL method was not only able to pattern the P3HT polymer lm easily, but also could induce a face-on molecular alignment of polymer P3HT for the nanopattern.…”

Maintaining nanoimprinting-induced face-on alignment in poly(3-hexylthiophene) nanopillars after thermal annealing

“…29 Recently, our group has presented a simple and cost-effective solvent-assisted room-temperature NIL (SART-NIL) method based on the NIL technique to fabricate the polymer nanostructure or induce the molecular alignment. [30][31][32][33] However, a comprehensive understanding of the NIL process in dening or reorienting the molecular alignment is unclear and the simultaneous determination of the polymer chain alignment and nanostructure morphology still has a long way to go.…”