Proceedings of 6th International Conference on Hybrid and Organic Photovoltaics (HOPV14)
Publication date: 1st March 2014
Standard BHJ solar cells comprising P3HT:PCBM as the active layer have been fabricated with the hygroscopic PEDOT:PSS as well as different new metal-oxide based hole transport layers from precursor solutions. The devices with a metal-oxide layer show a strongly increased stability compared to those fabricated with PEDOT:PSS. The Jsc stability was increased over a factor 100. The metal-oxide devices show remarkable air stability even under accelerated (85 %RH, 45°C) aging conditions.
Aiming to get deeper insight into the enhanced stability of these organic solar cells several electrical characterization techniques are employed at different stages of degradation. For the reference cells a degradation mechanism has been verified relating moisture ingress through the hole transporting layer into the device to a loss in carrier extraction efficiency. For this analysis an all‐in‐one characterization platform for dynamic electrical characterization of photocurrents (Paios) [ref. Neukom] is used and an opto‐electronic device model (Setfos) [ref. Häusermann] is employed for qualitative comparison. The manifold of applied measurement techniques joined with numerical simulations allows for quantitative analysis of parameters like charge carrier mobilities and charge doping/trap densities.
Transient Photocurrent for fresh cell (red) and at different aging times.
Neukom, M.; Züfle, S.; Ruhstaller, B. Reliable extraction of organic solar cell parameters by combining steady-state and transient techniques. Organic Electronics 2012, 13, 2910-2916. Häusermann, R.; Knapp, E.; Moos, M.; Reinke, N.; Flatz, T.; Ruhstaller, B. Coupled optoelectronic simulation of organic bulk-heterojunction solar cells: Parameter extraction and sensitivity analysis. Journal of Applied Physics 2009, 106, 104507.