Reactive Dedoping of Polymer Semiconductors To Boost Self-Powered Schottky Diode Performances

A facile and strategic junction tuning technology is reported to boost self-powered organic Schottky photodiode (OPD) performances by synergetic contributions of reactive dedoping effects. It is shown that dedoping poly(3-hexylthiophene-2,5-diyl) (P3HT) films with 1-propylamine (PA) solution significantly reduces not only acceptor-defect density but also intrinsic doping level, leading to dramatically enlarged depletion width of metal/polymer Schottky junctions, as confirmed by ultraviolet photoelectron spectroscopy and Mott–Schottky junction analyses. As a result, whole penetration regions of photons corresponding to absorption bands of P3HT can be fully covered by the depletion region of Schottky junctions, even without the assistance of external electric fields. In addition, it is shown that non-solvent exposure effects of PA dedoping further enable lower paracrystalline disorder and, thus, higher charge carrier mobility, by means of grazing incidence X-ray diffraction, field-effect mobility, and space...