Numerical investigation of photo-generated carrier recombination dynamics on the device characteristics for the perovskite/carbon nitride absorber-layer solar cell

Abstract

The nitrogenated holey two-dimensional carbon nitride (C2N) has been efficaciously utilized in the fabrication of transistors, sensors, and batteries in recent years, but lacks application in the photovoltaic industry. The C2N 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 (CH3NH3PbI3)-carbon nitride (C2N) layer solar cell and subsequently provided in-depth insight into the active-layerassociated recombination losses limiting the efficiency (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) cm(-3) with a uniform energy distribution of defects for all layers, we achieved an 11 of 24.16%. A con- siderable enhancement in power-conversion efficiency (eta similar to 27%) was perceived as we reduced the trap density to 10(14) 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) cm(-3) to achieve efficient device characteristics.