An n-type, new emerging luminescent polybenzodioxane polymer for application in solution-processed green emitting OLEDs

Abstract

Herein, we report polybenzodioxane polymer (PIM-1), a multifunctional n-type emitter with strong green luminescence, and its suitability as an electron transport layer for OLEDs devices. The Brunauer–Emmett–Teller (BET) test and photo-electrical properties of as-synthesized PIM-1 confirm the presence of large microporosity and excellent electron mobility. The photoluminescence (PL) spectroscopy shows the intense green emission at 515 nm upon 332 nm excitation wavelength. Moreover, the Hall effect study reveals the negative Hall resistivity, which indicates that PIM-1 possesses n-type semiconductor characteristics. It enables the highly-efficient polymer-based green LEDs with configuration; ITO (120 nm)/PEDOT:PSS (30 nm)/PIM-1 (100 nm)/LiF (1 nm)/Al (150 nm), which are fabricated by the sequential solution-processing method. The OLED incorporating PIM-1 thin layer achieves maximum current efficiency of 1.71 Cd A⁻¹ and power efficiency of 0.49 lm W⁻¹. Additionally, the electron mobility is found to be 4.4 × 10⁻⁶ cm² V⁻¹ s⁻¹. Hence, these results demonstrate that PIM-1 could be an ultimate choice as an n-type emitter for the next generation of advanced electronic devices.