The goal of this work is to make a contribution to the complex subject of organic solar cells degradation when operating in contact with ambient air. For this we built solar cells of the bulk heterojunction type composed of PTB7-Th (poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yebenzo [1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno [3,4-b]thiophene)-2-carboxylate-2-6-diyl)]) and PC71BM ([6,6]-Phenyl-C71-butyric acid methyl ester), respectively, as donor and acceptor materials of electrons. We present a series of current-voltage curves (J-V), both in the dark and under illumination, initially with the device immersed in an inert atmosphere and then exposing it to the ambient environment. J-V curves is then analyzed in terms of the Mott-Gurney equation, for measurements in dark, and by an analytical expression for the photocurrent, which allow us to check how the charge carrier mobility and the non-geminate recombination coefficient vary with time of exposure to air. We conclude that the charge carrier mobility (mu) for cells made with the PTB7-Th:PC71BM blend varies very little when in contact with air, and similar influence is observed on the recombination coefficient (k), since the Langevin coefficient reduction factor (zeta) is about 0.2 when the device is in inert atmosphere, reaching a value of almost 0.9 when exposed to air for 43 h.