The impact of SRH recombination on the current–voltage characteristic of organic and perovskite solar cells: a basic drift–diffusion framework

In this paper the impact of Shockley-Read-Hole (SRH) recombination on the performance of organic (OSCs) and perovskite (PSCs) solar cells is comparatively analyzed by the drift–diffusion model. It has been established that for OSCs SRH recombination dominantly affects short circuit current ( $$\:{J}_{sc}$$ ), while for PSCs open circuit voltage ( $$\:{V}_{oc}$$ ) is mostly affected, both resulting in a significant reduction of efficiency. Considering that one of the fundamental differences between organic materials and perovskites is the mobility of charge carriers, the influence of mobility on the loss of $$\:{J}_{sc}$$ and $$\:{V}_{oc}$$ due to SRH recombination in both types of solar cells was investigated. Higher $$\:{V}_{oc}$$ and $$\:{J}_{sc}$$ losses were observed in PSCs. The obtained results were explained by analyzing the operation of the devices in short-circuit and open-circuit. Unlike PSCs, in short-circuit of OSCs, a significant amount of charge carriers remains in the active layer. The pronounced SRH recombination appears which reduces the conductivity and therefore the drift current and consequently $$\:{J}_{sc}$$ . At open circuit, in both OSCs and PSCs, the drift current balances the diffusion current which is found to be independent of SRH recombination. The decrease in conductivity therefore leads to an increase in the electric field, thus lowering $$\:{V}_{oc}$$ . Obtained results are supported by experimental evidence from literature.