Operating Temperature of Nonfullerene Acceptor-Based Bulk Heterojunction Organic Solar Cells

摘要

A comprehensive study of the operating temperature (T_(cr)) of three nonfullerene(NF) acceptor-based bulk heterojunction organic solar cells (BHJ OSCs), twoconventional (OSC1 and OSC3) and one inverted (OSC2) structure, is presented.A quantitative analysis of the thermal power generated by photonabsorption in transport layers and electrodes, thermalization of photoexcitedcharge carriers, tail-state recombination, and resistive heating is conducted. Forall three OSCs, the dependence of operating temperature T_(cr) on the voltage issimulated and it is found that OSC1 and OSC2 operate at about 320 K andOSC3 at 319 K. It is also found that the thermal power generated due tothermalization (P_T) and absorption in other than the active layer (P_(Abs)~(ol)) in OSC3are smaller than those in both OSC1 and OSC2 but the thermal power generateddue to the resistive heating (P_R) is larger in OSC3 than in OSC1 andOSC2, leading to the net power absorbed in the active layer of OSC3 beinghigher than that in OSC1 and OSC2. Thus, although the operating temperatureof all three cells remains in the range from 320 to 321 K, OSC3 shows a betterphotovoltaic performance.