Fig. 3. Doping enhanced photovoltaic performance. (A) J-V curves of solar cells based on different combinations of charge extraction layers with standard thickness (NiO, NiMg(Li)O = 20 nm; TiOx, Ti(Nb)Ox = 10 nm). (B) Normalized PL transient decay curves of perovskite and perovskite at the controlled interfaces of NiO and NiMg(Li)O, solid lines are fitted results with a double exponential decay. The time interval during which the PL decays to 1/e of the initial intensity is defined as the characteristic lifetime (τ) of free carriers after photoexcitation. (C) and (D) show normalized transient photocurrent and photovoltage decay curves, respectibely based on undoped and doped charge carrier extraction layers. The charge transport (τt) and recombination time (τr) are again defined as the time interval during which the photocurrent or photovoltage decays to 1/e of the their initial value immediately after excitation.
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Fig. 4. Performance and stability of large size cells. (A) J–V curve of the best large cell endowed with anti–reflection film, (B) the corresponding IPCE spectrum and integrated Jsc, (C) the stability of the cells without sealing, based on different electron extraction layers of Ca (4 nm), LiF (1.5 nm) and Ti(Nb)Ox (10 nm) between PCBM and the Ag contact, the cells were kept in a dry cabinet (< 20% humidity) in the dark and measured in ambient air, (D) stability of sealed cells kept in the dark or under simulated solar light (AM 1.5, 100 mW cm–2, using a 420 nm UV light cut–off filter, surface temperature of the cell: 45° to 50°C, bias potential = 0 V).
/ sciencemag.org/content/early/recent / 29 October 2015 / Page 10 / 10.1126/science.aad1015
