Supplementary of Applied Physics Letters L12-07918
High
efficiency
and
high
photo-stability
zinc-phthalocyanine
based
planar
heterojunction solar cells with a double interfacial layer
Tae-Min Kim, Ji Whan Kim, Hyun-Sub Shim, and Jang-Joo Kima)
WCU Hybrid Materials Program, Department of Materials Science and Engineering and the
Center for Organic Light Emitting Diode, Seoul National University Seoul 151-74, South
Korea
Fig.S1 shows the time-of-flight secondary ion mass spectrometry (TOF-SIMS) data of (a)
fullerene (C60)/zinc phthalocyanine (ZnPc)/CuI/indium tin oxide (ITO) and (b)
C60/ZnPc/CuI/MoO3/ITO samples, which include the mass profile of Cu2O, CuO and I2. We
could not find the existence of Cu2O or I2 in the C60/ZnPc/CuI/ITO sample. Note that CuO
exists in the C60/ZnPc/CuI/ITO sample after UV irradiation. However the profile is the same
as the pristine sample without the UV irradiation, indicating that the formation of CuO is not
the origin of the diffusion of Cu-.
Insertion of the MoO3 layer between the ITO and CuI induces the formation of Cu2O, I2
and CuMoOx complexes and prevents the diffusion of Cu atoms or ions under UV
illumination.
FIG. S1. TOF-SIMS depth profiles of the samples in the negative mode with the structure of
(a) ITO/CuI (3 nm)/ZnPc (25 nm)/C60 (40 nm), and (b) ITO/MoO3 (3 nm)/CuI (3 nm)/ZnPc
(25 nm)/C60 (40 nm).