Improved electron collection in fullerene via caesium iodide or carbonate by means of annealing in inverted organic solar cells

Abstract

Inverted organic photovoltaic cells (IOPVCs), based on the planar heterojunction C60/CuPc, were grown using MoO3 as anode buffer layer and CsI or Cs2CO3 as cathode buffer layer (CBL), the cathode being an ITO coated glass. Work functions, Φ f , of treated cathode were estimated using the cyclic voltammetry method. It is shown that Φ f of ITO covered with a Cs compounds is decreased. This decrease is amplified by the annealing. It is shown that the thermal deposition under vacuum of the CBL induces a partial decomposition of the caesium compounds. In parallel, the formation of a compound with the In of ITO is put in evidence. This reaction is amplified by annealing, which allows obtaining IOPVCs with improved efficiency. The optimum annealing conditions is 150• C for 5 min.

Assessing the suitability of copper thiocyanate as a hole-transport layer in inverted CsSnI3 perovskite photovoltaics

“…2(d) that the perovskite film is compact, there is also a high density of grain boundaries. The indium 3d peaks are clearly resolved in the high resolution (HR) XPS spectrum of the perovskite film deposited onto CuSCN | ITO, with a binding energy consistent with that of ITO 26 , 27 (Figure S7 ) confirming that the underlying ITO is probed using this technique. The complete absence of Cu, N and S in the HR-XPS spectra (Figure S6 ) is consistent with the complete displacement of the CuSCN upon spin casting the perovskite layer.…”