In this study, two different n-CdS/p-Cu2S solar cells were prepared by evaporating Cu at different substrate temperatures (200 K and 300 K) by vacuum evaporation method on a single crystal CdS semiconductor. Field emission scanning electron microscope images showed that the Cu layer obtained at a temperature of 200 K was composed of nanoparticles in accordance with the soliton growth mechanism. Cu film thickness was determined as 395 0.76 nm at 300 K substrate temperature and 187 0.45 nm at 200 K substrate temperature. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the solar cells were examined for 12 weeks in dark and light environments. Open-circuit voltage (V-oc), short-circuit current (I-sc), maximum power (P-max), filling factor and efficiency (eta) were calculated from I-V measurements. For the prepared solar cells, the highest efficiency value was obtained in the 7th week (eta= 0.1360) at 200 K substrate temperature, while it was obtained in the 5th week (eta = 0.0384) at 300 K substrate temperature. From C-V measurements, donor density (N-d) and barrier potential (V-bi) were calculated. The solar cell produced at 200 K substrate temperature has higher donor density (1st week 2.99 x 10(16) cm(-3)) and barrier potential values (12th week 0.411 V). At the end of the 12-week period, the deterioration rate of solar cells created at 200 K and 300 K substrate temperatures was 51% and 94%, respectively.