TY - JOUR
T1 - Effects of pressure on nano- and micro-scale morphological changes in conjugated polymer photovoltaic cells
AU - Agyei-Tuffour, Benjamin
AU - Rwenyagila, Egidius Rutatisbwa
AU - Asare, Joseph
AU - Kana, Martiale Gaetan Zebaze
AU - Soboyejo, Winston O.
N1 - Publisher Copyright:
© Copyright 2016 Materials Research Society.
PY - 2016/10/28
Y1 - 2016/10/28
N2 - This paper presents the results of an experimental study of the effects of pressure on polymer chain alignments in poly(3-hexylthiophene) and [6,6]-phenyl C61-butyric acid methyl ester (P3HT:PCBM) blends that are used in bulk heterojunction organic photovoltaic cells (OPVs). The P3HT:PCBM blends on glass were subjected to pressure and annealing at 140 °C. The surface morphologies, nano-/micro-structures and the chain alignments were analyzed using atomic force microscopy techniques and grazing incidence x-ray scattering. The current-voltage characteristics of the resulting devices are also shown to change significantly with changes in the nano-/micro-structures. The polymer chains were aligned in the direction of the applied pressure (edge-on), which reduced the lamellae spacing between the polymer units and increased the degree of crystallinity. The increased crystallinity plays significant role in the current-voltage enhancements. The implications of the study are discussed for the design and control of the nano/microstructures of bulk heterojunction organic solar cells.
AB - This paper presents the results of an experimental study of the effects of pressure on polymer chain alignments in poly(3-hexylthiophene) and [6,6]-phenyl C61-butyric acid methyl ester (P3HT:PCBM) blends that are used in bulk heterojunction organic photovoltaic cells (OPVs). The P3HT:PCBM blends on glass were subjected to pressure and annealing at 140 °C. The surface morphologies, nano-/micro-structures and the chain alignments were analyzed using atomic force microscopy techniques and grazing incidence x-ray scattering. The current-voltage characteristics of the resulting devices are also shown to change significantly with changes in the nano-/micro-structures. The polymer chains were aligned in the direction of the applied pressure (edge-on), which reduced the lamellae spacing between the polymer units and increased the degree of crystallinity. The increased crystallinity plays significant role in the current-voltage enhancements. The implications of the study are discussed for the design and control of the nano/microstructures of bulk heterojunction organic solar cells.
KW - photoluminescence
KW - polymer chain alignment
KW - pressure effects
KW - x-ray scattering
UR - http://www.scopus.com/inward/record.url?scp=84989246274&partnerID=8YFLogxK
U2 - 10.1557/jmr.2016.344
DO - 10.1557/jmr.2016.344
M3 - Article
AN - SCOPUS:84989246274
SN - 0884-2914
VL - 31
SP - 3187
EP - 3195
JO - Journal of Materials Research
JF - Journal of Materials Research
IS - 20
ER -