Low‐Cost, Organic Light‐Emitting Electrochemical Cells with Mass‐Producible Nanoimprinted Substrates Made Using Roll‐to‐Roll Methods

Abstract

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‐5‐(2‐ethylhexyloxy)‐1,4‐phenylene vinylene]) and (“super‐yellow” poly(p‐phenylene vinylene)) (SY‐PPV) are fabricated by solution‐based spin‐coating methods, which can in practice be replaced by roll‐to‐roll methods. The corrugated PLECs with SY‐PPV show high brightness of 1740 cd cm−2 and 2.1 times greater efficiency without changing the original spectrum or angular dependence. This successful combination of corrugated substrates and PLECs is one of the best examples of a promising cost‐effective, high‐performance lighting technology.