TY - JOUR
T1 - Reducing exciton-polaron annihilation in organic planar heterojunction solar cells
AU - Verreet, Bregt
AU - Bhoolokam, Ajay
AU - Brigeman, Alyssa
AU - Dhanker, Rijul
AU - Cheyns, David
AU - Heremans, Paul
AU - Stesmans, Andre
AU - Giebink, Noel C.
AU - Rand, Barry P.
N1 - Publisher Copyright:
© 2014 American Physical Society.
PY - 2014/9/4
Y1 - 2014/9/4
N2 - We investigate the relationship between charge concentration, exciton concentration, and photocurrent generation in fullerene-containing heterojunction diodes. Impedance measurements on C60 diodes reveal a charge buildup at the C60/bathocuproine (BCP) interface that can be swept out under reverse bias. In solar cell structures, a similar charge buildup is observed in dark conditions, and increases as a function of incident light intensity. Photoluminescence measurements reveal that the C60 exciton concentration is voltage dependent, explained via the process of exciton-polaron annihilation. This process has a negative impact on the generated photocurrent of the solar cells and thereby decreases the fill factor. A combination of electroabsorption, photoluminescence, and impedance measurements reveal a decrease in charge buildup and the associated exciton-polaron annihilation through the use of a BCP/3,4,9,10-perylenetetracarboxylic bis-benzimidazole/Ag cathode.
AB - We investigate the relationship between charge concentration, exciton concentration, and photocurrent generation in fullerene-containing heterojunction diodes. Impedance measurements on C60 diodes reveal a charge buildup at the C60/bathocuproine (BCP) interface that can be swept out under reverse bias. In solar cell structures, a similar charge buildup is observed in dark conditions, and increases as a function of incident light intensity. Photoluminescence measurements reveal that the C60 exciton concentration is voltage dependent, explained via the process of exciton-polaron annihilation. This process has a negative impact on the generated photocurrent of the solar cells and thereby decreases the fill factor. A combination of electroabsorption, photoluminescence, and impedance measurements reveal a decrease in charge buildup and the associated exciton-polaron annihilation through the use of a BCP/3,4,9,10-perylenetetracarboxylic bis-benzimidazole/Ag cathode.
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U2 - 10.1103/PhysRevB.90.115304
DO - 10.1103/PhysRevB.90.115304
M3 - Article
AN - SCOPUS:84907000542
SN - 1098-0121
VL - 90
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 11
M1 - 115304
ER -