The nitrogenated holey two-dimensional carbon nitride (${\mathrm{C}}_2\mathrm{N}$) has been efficaciously utilized in the fabrication of transistors, sensors, and batteries in recent years, but lacks application in the photovoltaic industry. The ${\mathrm{C}}_2\mathrm{N}$ possesses favorable optoelectronic properties. To investigate its potential feasibility for solar cells (as either an absorber layer/interface layer), we foremost detailed the numerical modeling of the double-absorber-layer–methyl ammonium lead iodide (${\mathrm{CH}}_3{\mathrm{NH}}_3{\mathrm{PbI}}_3$) –carbon nitride (${\mathrm{C}}_2\mathrm{N}$) layer solar cell and subsequently provided in-depth insight into the active-layer-associated recombination losses limiting the efficiency ($\mathsf{\eta }$) of the solar cell. Under the recombination kinetics phenomena, we explored the influence of radiative recombination, Auger recombination, Shockley Read Hall recombination, the energy distribution of defects, Band Tail recombination (Hoping Model), Gaussian distribution, and metastable defect states, including single-donor (0/+), single-acceptor (−/0), double-donor (0/+/2+), double-acceptor (2/−/0−), and the interface-layer defects on the output characteristics of the solar cell. Setting the defect (or trap) density to ${10}^{15}{\mathrm{cm}}^{-3}$ with a uniform energy distribution of defects for all layers, we achieved an$\mathsf{\eta }$ of 24.16%. A considerable enhancement in power-conversion efficiency ($\mathsf{\eta }~27\%$) was perceived as we reduced the trap density to ${10}^{14}{\mathrm{cm}}^{-3}$ for the absorber layers. Furthermore, it was observed that, for the absorber layer with double-donor defect states, the active layer should be carefully synthesized to reduce crystal-order defects to keep the total defect density as low as ${10}^{17}{\mathrm{cm}}^{-3}$ to achieve efficient device characteristics.

Herein we foremost detailed the numerical modeling of the double absorber layer- methyl ammonium lead iodide– carbon nitride layer solar cell and subsequently provided in-depth insight on the active layer associated with dominant radiative and non-radiative recombination losses limiting the efficiency ( ) of the solar cell. Under recombination kinetics phenomena, we explored the influence of Radiative recombination, Auger recombination, Shockley Read Hall recombination, the energy distribution of defects; Band Tail recombination (Hoping Model), Gaussian distribution, metastable defect states including single donor (0/+), single acceptor (-/0), Double Donor (0/+/2+), double acceptor (2/-/0-), and the interface layer defects on the output characteristics of the solar cell. Setting defect (or trap) density to with uniform energy distribution of defects for all the layers, we achieved the of 24. 16 %. A considerable enhancement in power conversion efficiency was perceived as we reduced the trap density to for the absorber layers. Further, it was observed that for the absorber layer with double donor defect states, the active layer should be carefully synthesized to reduce crystal order defects to keep the total defect density as low as to achieve efficient device characteristics