Abstract
In this work, a relative broad set of elements of material physics was considered to explore their effects on the output characteristics of a lead-free perovskite solar device, in an attempt of improving its performance. The approach is inspired by the recent refined methods in physics of semiconductors and optics, and is based on the most promising results from recent work. Calculations and modeling are performed with the thin films photovoltaic (PV) software Solar Cell Capacitance Simulator on one dimension (SCAPS-1D), which helped to model defect states (DS) and interfaces between layers to be as closed as possible to a real device. Taking into consideration the current challenges that are lead-free, nanoscale, and more stable architectures, defects states and light trapping, parameters such as doping concentration, thicknesses, and temperature were pinpointed as remarkably affecting the characteristics of the cell. The doping concentrations around 1015cm-3 and 1017cm-3 were involved for the acceptor-type absorber and the donor-type buffer coats, respectively. Moreover, and as a novelty of this contribution, for only 1 mu m depth of active coat material and nanometer thicknesses of other layers, very promising PV performances were obtained: an open-circuit voltage Voc=0.8V, a high short-circuit current Jsc=33.89mA/cm2, a fill factor = 84.77%, and an efficiency eta =23%. They are currently, the highest theoretically obtained performances for lead-free architectures, considering the closed to real device environment. Modeling a no DS structure and not displaying the effects of interfaces help achieving a PCE of 28%. The effects of light transmission/reflection ratios at front/back contact respectively, on quantum efficiency and J-V characteristics were also investigated. These results constitute an appreciable step forward on enhancement of perovskite solar cells devices.