Effects of carrier mobility,energy gap,and excitation size on the performance of single layer organic solar cells

A model of universal single layer organic solar cells in metal-insulator-metal (MIM) representation involving field-depen-dent carrier mobility is set up. The current-voltage characteristics as well as the distribution of electron density,hole density and recombination rate on a set of parameters are simulated. Subsequently,the dependences of the short-circuit current density (Jsc) and open-circuit voltage (Voc) on the electron and hole zero-field mobility,excitation generation rate,energy gap,as well as electron-hole pair distance in an excitation are investigated. It is demonstrated that the enhancement of either the electron mobility or the hole mobility can contribute to the increase of Jsc in the devices. The increase of the hole mobility can lead to the improvement of both Jsc and Voc,and the simultaneous increase of the electron mobility and hole mobility will greatly elevate Jsc but maintain a steady Voc. Additionally,all the increases of the excitation generation rate,energy gap and electron-hole pair distance are beneficial to both the remarkable increases of Jsc and Voc of the devices.