Absorber Doping Controls Internal Electric Field and Transport- Recombination Trade-Off in Perovskite Solar Cells: A SILVACO ATLAS TCAD Study

Abstract Perovskite solar cells combine strong optical absorption with favorable carrier-transport properties, but their performance remains highly sensitive to the electrical properties of the absorber, particularly its doping level. In this work, SILVACO ATLAS TCAD is used to investigate how absorber doping modifies the electrical response of a planar \(\:{\text{C}\text{H}}_{3}{\text{N}\text{H}}_{3}{\text{P}\text{b}\text{I}}_{3}\) absorber layer in an \(\:\text{I}\text{T}\text{O}/\text{N}\text{i}\text{O}/{\text{C}\text{H}}_{3}{\text{N}\text{H}}_{3}{\text{P}\text{b}\text{I}}_{3}/\text{Z}\text{n}\text{O}/\text{A}\text{u}\) architecture. Photovoltaic parameters, including open-circuit voltage \(\:\left({\text{V}}_{\text{o}\text{c}}\right)\), short-circuit current density \(\:\left({\text{J}}_{\text{s}\text{c}}\right)\), fill factor (FF), efficiency \(\:\left({\eta\:}\right)\), together with effective series and shunt resistances, were extracted from the simulated current–voltage characteristics. Spatially resolved energy-band bending, electrostatic potential, internal electric field, photogeneration, and recombination profiles were then analyzed to connect the microscopic electrostatic response to the macroscopic photovoltaic behavior. The results show that a doping concentration of \(\:5\times\:{10}^{16}\:\text{c}{\text{m}}^{-3}\) provides the compromise between carrier transport, resistive losses, and recombination, yielding a maximum efficiency of 23.35%. Two competing regimes emerge: from low to intermediate doping, improved conductivity and interfacial electrostatics enhance charge extraction, whereas at high doping, field localization and strongly increased bulk recombination progressively reduce carrier collection despite continued gains in some voltage- and fill-factor-related indicators. Because photogeneration remains essentially unchanged, the efficiency optimum results from a transport-recombination trade-off rather than an optical effect