Voltage dependence of equivalent circuit parameters of bilayer organic photovoltaics

Despite the very different underlying physics of organic photovoltaics (OPVs), inorganic p-n junction’s Shockley’s diode equation is often applied to describe current density–voltage (JV) curves OPVs. The model parameters, including saturation current, ideality factor, series, and parallel resistances, are usually extracted treated as constants in JV curve analyses. In this work, we develop a drift-diffusion bilayer interface (DD-BI) for OPVs, which treats donor–acceptor (D–A) heterojunction using detailed balance between densities polaron pairs, free electrons, holes. From DD-BI model, derive equation, form, but each parameter explicitly written terms D–A properties. We call self-consistent (SCD) it consistent with results provided that key parameters from simulation data. By studying effects light intensity carrier mobility, find Shockley SCD voltage dependent because space charge accumulation around heterojunction. Our models successful explaining common discrepancies OPV analyses, such validity fitting series resistance, deviation factor theoretical values, resistance values under dark conditions. provide better understanding OPVs how can capture its equation.