TY - JOUR
T1 - Structural templating of chloro-aluminum phthalocyanine layers for planar and bulk heterojunction organic solar cells
AU - Verreet, Bregt
AU - Müller, Robert
AU - Rand, Barry P.
AU - Vasseur, Karolien
AU - Heremans, Paul
N1 - Funding Information:
The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement 212311 of the ONE-P project. K.V. acknowledges the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen) for financial support.
PY - 2011/12
Y1 - 2011/12
N2 - Chloro-aluminum phthalocyanine (ClAlPc) film growth on 1H,1H,2H,2H- perfluorodecyltrichlorosilane (FDTS) and MoO3 is studied and correlated to ClAlPc/C60 solar cell performance for both planar and bulk heterojunction (HJ) architectures. On top of unheated substrates, ClAlPc films grow amorphous independent of the substrate surface. When heated to 105 °C, ClAlPc grows with a face-on orientation on MoO3, with a crystalline phase I-like absorption profile. On FDTS, the film is optically characterized as phase II, and adopts an edge-on orientation. Implemented in planar HJ cells, the latter films show a substantially higher current compared to the other growth conditions, leading to 3% efficient cells. This current increase is investigated with spectral response and reflectivity measurements, and is found to be related to a more efficient exciton dissociation. Next, ClAlPc and C60 are co-evaporated on FDTS and MoO3 modified ITO substrates to fabricate bulk HJ devices. Notably, we find that when a thin pure "templating" layer of ClAlPc is grown first, the subsequently grown ClAlPc:C60 bulk HJ propagates the templating effect, and films show a higher crystallinity than without this templating layer, with higher fill factors as a result. On MoO3, this approach yields efficiencies above 4%.
AB - Chloro-aluminum phthalocyanine (ClAlPc) film growth on 1H,1H,2H,2H- perfluorodecyltrichlorosilane (FDTS) and MoO3 is studied and correlated to ClAlPc/C60 solar cell performance for both planar and bulk heterojunction (HJ) architectures. On top of unheated substrates, ClAlPc films grow amorphous independent of the substrate surface. When heated to 105 °C, ClAlPc grows with a face-on orientation on MoO3, with a crystalline phase I-like absorption profile. On FDTS, the film is optically characterized as phase II, and adopts an edge-on orientation. Implemented in planar HJ cells, the latter films show a substantially higher current compared to the other growth conditions, leading to 3% efficient cells. This current increase is investigated with spectral response and reflectivity measurements, and is found to be related to a more efficient exciton dissociation. Next, ClAlPc and C60 are co-evaporated on FDTS and MoO3 modified ITO substrates to fabricate bulk HJ devices. Notably, we find that when a thin pure "templating" layer of ClAlPc is grown first, the subsequently grown ClAlPc:C60 bulk HJ propagates the templating effect, and films show a higher crystallinity than without this templating layer, with higher fill factors as a result. On MoO3, this approach yields efficiencies above 4%.
KW - Bulk heterojunction
KW - Chloro-aluminum phthalocyanine
KW - FDTS
KW - Organic solar cell
KW - Structural templating
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U2 - 10.1016/j.orgel.2011.08.031
DO - 10.1016/j.orgel.2011.08.031
M3 - Article
AN - SCOPUS:80053517686
SN - 1566-1199
VL - 12
SP - 2131
EP - 2139
JO - Organic Electronics
JF - Organic Electronics
IS - 12
ER -