The investigation of stability of n-CdS/p-Cu2S solar cells prepared by cold substrate method
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 (η) were calculated from I–V measurements. For the prepared solar cells, the highest efficiency value was obtained in the 7th week (η= 0.1360) at 200 K substrate temperature, while it was obtained in the 5th week (η = 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 × 1016 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.