Green solvent processed tetramethyl-substituted aluminum phthalocyanine thin films as anode buffer layers in organic light-emitting diodes

Abstract

This study presents the use of a green solvent processed tetramethyl-substituted aluminum phthalocyanine (AlMePc) thin film as an anode buffer layer in an organic light-emitting diode (OLED). The aim of the study was to probe the feasibility of green processing conditions for OLED fabrication. The hole-blocking properties of the AlMePc layer were determined to achieve devices with more balanced charge injection and transport processes. We achieved a significantly enhanced luminance of 11 790 cd m⁻², which is twice that of a comparable diode without this anode buffer layer. Additionally, a higher luminous efficiency and power efficiency were obtained for the AlMePc-based OLED than those for a PEDOT:PSS-based diode. Furthermore, the improved charge balance in the OLED achieved by using the AlMePc layer along with its non-aqueous, organic processing methods yielded a maximum half-lifetime of 1860 min at a driving current density of 100 mA cm⁻².