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

Abstract

A comprehensive study of the operating temperature () of three nonfullerene (NF) acceptor‐based bulk heterojunction organic solar cells (BHJ OSCs), two conventional (OSC1 and OSC3) and one inverted (OSC2) structure, is presented. A quantitative analysis of the thermal power generated by photon absorption in transport layers and electrodes, thermalization of photoexcited charge carriers, tail‐state recombination, and resistive heating is conducted. For all three OSCs, the dependence of operating temperature on the voltage is simulated and it is found that OSC1 and OSC2 operate at about 320 K and OSC3 at 319 K. It is also found that the thermal power generated due to thermalization (PT) and absorption in other than the active layer () in OSC3 are smaller than those in both OSC1 and OSC2 but the thermal power generated due to the resistive heating (PR) is larger in OSC3 than in OSC1 and OSC2, leading to the net power absorbed in the active layer of OSC3 being higher than that in OSC1 and OSC2. Thus, although the operating temperature of all three cells remains in the range from 320 to 321 K, OSC3 shows a better photovoltaic performance.