Interface engineering for enhancement in performance of organic/inorganic hybrid heterojunction diode

Abstract

Interface engineering through self-assembled monolayer (SAM) is an efficient way for tailoring the work function and electronic property of surface; enhancing the charge injection efficiency and device performance for microelectronics applications. Despite this, there is lack of study on effect of interface engineering of organic/inorganic hybrid heterojunction diode through SAM. Here, we have reported the surface engineering for tailoring the surface work function, electronic property, enhancement in injection efficiency and device performance. Therefore, Zinc Oxide (ZnO) film surface was modified with SAM before formation of hybrid ZnO/poly(3-hexylthiophene) (P3HT) heterojunction diode and compared with unmodified ZnO/P3HT diode. Prior to measurement of J-V heterojunction characteristics, both interfaces were characterized using absorption spectra, grazing incidence X-ray diffraction (GIXD), scanning electron microscopy (SEM), atomic force microscopy (AFM), kelvin probe force microscopy (KPFM). The modification of ZnO with SAM prior to heterojunction formation allows the better fabrication of diodes featuring ∼10 fold enhancement in rectification ratio at ±3 V and ∼32 fold enhancement in forward current density at 3 V with advancement in electronic device parameter. The enhancement in electrical characteristics are also discussed taking into account the absorption spectra, structural analysis, surface morphology, topography, surface potential, barrier height, and the energy band diagram of SAM's modified and unmodified diodes. Our study has cemented a path to further improve the device performance and parameter for electronic applications.