is thus seen as having the potential to open up new markets for high efficiency lighting. However, reducing manufacturing costs is critical because most OLED lighting still costs too much for the average consumer. As Reineke points out, the only way that costs are likely to come down significantly is through the use of roll-to-roll fabrication methods. [5] Polymer LECs (PLECs) based on fluorescent conjugated poly mers (FCPs) and ion conductors are among the most promising candidates for future lighting systems. [7][8][9][10][11][12][13] PLECs have simple singlelayer structures, which can be fabricated using roll-to-roll methods, using solutions containing both FCPs and ion conductors. [14][15][16][17][18][19] When an external voltage (V a ) higher than the threshold voltage (V th = E g /e: E g is the bandgap of the FCP and e is the elementary charge) is applied between the electrodes, light is generated as a p-n or p-i-n junction is formed as a result of in situ electrochemical doping. [7][8][9][10]20] PLECs have many other advantages, e.g., they can be fabricated using air-stable electrodes and thicker active layers. [21] So in addition to having simple single-layer structures, their other advantages make PLECs particularly well suited to manufacturing by roll-to-roll methods. In addition, it has been reported that certain low-molecularweight compounds, such as pentacene, carbene, and metal complexes, can be used to enable color tuning and improve efficiency. [11,[22][23][24][25][26][27] Realizing high efficiency organic lighting will require more effective light outcoupling technologies. [28][29][30][31][32][33][34][35][36] This is because in conventional organic light-emitting devices, ≈80% of the emitted light is optically trapped between the ITO and organic layers (ITO/organic modes) and in the glass substrate (substrate modes) and lost, and only around 20% of the emitted light can typically be extracted from the devices. In OLEDs, various approaches to enhancing outcoupling have been studied. [28][29][30][31][32][33][34][35] However, there are issues of wavelength selectivity, non-Lambertian angular emission (i.e., the directional problem), and production cost with regard to application of these techniques. To address these issues, Forrest and co-workers developed highly efficient light extraction technologies using a sub anode grid. [35] We, too, have developed efficient Next-generation, power-efficient organic lighting systems, which ideally would be low-cost and mass-producible, are urgently needed because more than 20% of total electricity use goes to lighting. This study presents polymer light-emitting electrochemical cells (PLECs) made using mass-producible nanoimprinted corrugated substrates, which effectively improve light extraction efficiency. The corrugated substrates are fabricated using roll-to-roll methods, using self-assembled block copolymers on glass and film substrates (glass: 0.45 m × 0.55 m, film: 0.6 m wide).
Using the glass-type corrugated substrates, two PLECs based on (poly[2-methoxy...
