Temperature-dependent device performance of organic photovoltaic cells based on a squaraine dye

We have systematically investigated the temperature-dependent device performance of organic photovoltaic (OPV) cells based on a squaraine dye. The 2,4-bis[4-(N,N-diisobutylamino)-2,6-dihydroxyphenyl] squaraine:[6,6]-phenyl C-71 butyric acid methyl ester (DIBSQ:PC70BM) OPV devices were fabricated and characterized under 100 mW cm(-2) (AM1,5G solar spectrum) in a temperature range from 285 to 360 K. The temperature-dependent photovoltaic parameters such as open-circuit voltage (V-oc),short-circuit current density (J(sc)), fill factor (FF) and power conversion efficiency (PCE) were studied in detail. The increasing temperature led to an improvement of J(sc) and FF, which should be ascribed to the enhanced carrier mobilities and improved electrode/active layer contact thus the improvement of photocurrent extraction at an elevated temperature. However, the V-oc decrease in the same period due to the carrier recombination of the OPV device. The increase in the J(sc) and FF overtakes the decrease in the V-oc with increasing temperature, resulting in a significantly improved PCE at elevated temperature. This study indicated that the DIBSQbased BHJ cells has promising potential for the practical application under changeable temperature environment. (C) 2016 Elsevier B.V. All rights reserved.