An antireflection transparent conductor with ultralow optical loss and high electrical conductance

Abstract

Transparent conductors (TCs) are essential elements in a wide range of optoelectronic devices, such as light emitting diodes, displays and solar cells, as they allow applying or generating electrical signals without incurring in optical loss (OL) [1]. By exploiting the destructive interference between light beams reflected at the interfaces, the reflection (R) and OL of a multilayer TC can be minimized. This is achieved through optimal design of film's thicknesses using Transfer Matrix Method (TMM) and proper selection of materials. In our experiments, we developed an antireflection TC (AR-TC) structure in which a 12nm Silver film is sandwiched in between TiO 2 and Al-doped Zinc Oxide (AZO). TiO 2 and AZO thicknesses were varied to find the optimal combination for minimum R and OL. Fig. 1a, 1b and 1c show simulation results with clear dependence of transmission (T), R and absorption (A) on TiO 2 and AZO thicknesses (OL=R+A).