Laminated indium-oxide/molybdenum-oxide nanocomposites for high-work-function electrodes in organic photovoltaics and capacitor devices

Abstract

Research on the development of transparent conductive oxides (TCOs) has been rapidly progressing. However, the limitations of the work function (WF), charge mobility, and surface roughness of TCOs hinder their widespread use in optoelectronic devices. In this study, we fabricated an atomic layer deposited (ALD)-transparent conductive electrode based on In2O3:MoOX nanolaminates with low resistivity (240 μΩ·cm) and high near-infrared region transmittance (∼90 %). The performance of In2O3:MoOX nanolaminates with high mobility (92.6 cm2/V·s) and WF (5.03 eV) was examined in organic photovoltaics (OPVs) and metal–insulator-metal (MIM) capacitors. In OPVs, the high WF of the proposed In2O3:MoOX nanolaminates simplifies the process by eradicating the requirement of the hole-transport layer (HTL). In this study, the In2O3:MoOX nanolaminates replaced PEDOT:PSS, a widely used HTL, thereby maintaining an efficiency greater than 90 % from its initial value after 500 h in a 1-sun environment. Further, in the MIM capacitor, the In2O3:MoOX nanolaminate-based capacitor demonstrated a high capacitance at high frequencies (1 MHz) and substantially low leakage current owing to its higher WF than those of conventional TiN-based capacitors. Thus, the diverse functionality of the proposed In2O3:MoOX nanolaminates demonstrated their excellent suitability for other optoelectronic devices.