High light-extracting efficiency for OLED directly fabricated on double-side nanotextured silica substrate.

One economical method for extracting the light loss from both the waveguide mode and substrate is demonstrated. Pillar arrays with different scales are created on the two sides of a silica substrate by inductively coupled plasma etching following a colloidal masking. The quasi-periodic Bragg scattering structure on a silica/ITO interface led to a two-fold current efficiency without introducing a spectral shift or directionality. Meanwhile, the subwavelength-scaled antireflection structure on a silica/air interface produced further increases in efficiency by 40%. The organic light-emitting device directly fabricated on the double-sided nanotextured silica substrate reached an overall enhancement factor of ~2.8 with the current efficiency.