Bulk heterojunction organic solar cells with four different Urbach’s tail width energies (E U ) are simulated, and the combined influence of E U and charge carrier mobility on the short circuit current (J sc ) , open circuit voltage (V oc ) , fill factor (FF), power conversion efficiency (PCE), Langevin and tail state recombination is investigated. The results show that J sc decreases more drastically with increasing E U in the lower mobility range and then asymptotically converges to a single value in the large mobility range. Likewise, with the increase in mobility, V oc decreases nearly linearly with different slopes depending on different E U in the lower mobility range and then different slopes converge to a single slope in the larger mobility range. Thus, V oc becomes E U independent in the higher mobility range. Furthermore, it is found that by increasing E U , the maximum values of FF and PCE shift towards the higher mobility range. It is shown that the influence of combined optimization of E U and mobility enhances both FF and PCE, but its effect on FF is much more significant than that on PCE.
|Number of pages||9|
|Journal||Journal of Materials Science: Materials in Electronics|
|Early online date||14 May 2019|
|Publication status||Published - Jun 2019|