Publication Date:
2016-12-09
Description:
A combination of transient and static techniques has been applied to bulk-heterojunction solar-cells to gain insight into the influence of charge-carrier dynamics and of energy level shifts in the vicinity of the cathode on the open-circuit voltage. Devices with a different thermal-annealing history but with similar active layer-morphology were compared. P3HT:PC 60 BM bulk heterojunction solar-cells with a standard ITO/PEDOT:PSS/active-layer/Al were investigated. We show that the open-circuit voltage increase that occurs when a sample is annealed before or after cathode deposition is due roughly one third to a shift between the energetics of the photoactive blend adjacent to the cathode and that in the bulk of the photoactive layer and roughly two thirds to a significant increase in the charge-carrier lifetime for this type of solar-cell.
Print ISSN:
0021-8979
Electronic ISSN:
1089-7550
Topics:
Physics
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