Modulation of indium–tin oxide work function by a versatile self-assembled monolayer measured with the scanning Kelvin nanoprobe

Abstract

In molecular optoelectronics, high-quality contacts at electrode|organics interfaces are crucial for charge carriers to efficiently flow through and therefore play a critical role on device performance. Electrode surface morphology, adhesibility, wettability, and work function are thus many parameters that must be accurately controlled, which is achievable using self-assembling monolayer (SAM) surface chemistry. Herein, we employ this technique to alter the electronic and surface energy-related properties of indium–tin oxide (ITO). In comparison to unmodified ITO, the newly introduced SAM-derivatized surface exhibits limited wettability and considerably higher work function (ΔΦ = ~1.2 eV). Several applications are proposed for this organic coating, notably at the anode of organic light-emitting diode (OLED) devices for decreasing the hole injection barrier or as an atmospherically stable protective layer in the coatings industry.