Impact of capture/emission time constant at donoracceptor interface on current-voltage characteristics of hybrid organic/inorganic quantum dot solar cells

Abstract

In this letter, the capture/emission time constant ( $\tau$ ), which depends on electronic coupling between the materials and structural/energetic disorder at the donor–acceptor interface, is considered in the model of hybrid organic/inorganic quantum dot (QD) solar cells as a factor that is responsible for degradation in solar cell parameters via an undesirable s-shape in the current–voltage (I–V) characteristic. In the model, charge transport is described by a drift-diffusion approximation and a set of coupled rate equations in transport layers and QDs, respectively. The analysis has revealed that the magnitude of accumulated photo-generated electrons at the QD interface and imbalanced carrier extraction from the active region is the key factors for the appearance of s-kink in the I–V characteristic.