GaInN‐Based Blue LED with a PEDOT/PSS Hole Transport Layer

Abstract

In this study, a nitride‐based blue PEDOT‐LED is fabricated and a preliminary assessment of the device characteristics is done. To prevent detaching of the PEDOT/PSS layer from the LED substrate when immersing in water or developing solution, Ag was deposited on top of the PEDOT/PSS layer. Additionally, exfoliation is suppressed by reducing the developing time and protecting the wafer edge with a photoresist. Different etching methods for Ag and PEDOT/PSS are investigated. The Ar ion‐beam etching resulted in uniform and flat‐etched surfaces. Regarding the performance of the PEDOT‐LEDs, a high Mg‐doping concentration of 1.0 × 1020 cm−2 leads to a relatively low threshold current voltage in the V–I characteristics. However, for the PEDOT‐LED with p‐Al0.25Ga0.75 N EBL, a steep light output saturation is observed at high current density when analyzing the L–I characteristics.