TY - JOUR
T1 - Post-assembly atomic layer deposition of ultrathin metal-oxide coatings enhances the performance of an organic dye-sensitized solar cell by suppressing dye aggregation
AU - Son, Ho Jin
AU - Kim, Chul Hoon
AU - Kim, Dong Wook
AU - Jeong, Nak Cheon
AU - Prasittichai, Chaiya
AU - Luo, Langli
AU - Wu, Jinsong
AU - Farha, Omar K.
AU - Wasielewski, Michael R.
AU - Hupp, Joseph T.
PY - 2015/3/11
Y1 - 2015/3/11
N2 - Dye aggregation and concomitant reduction of dye excited-state lifetimes and electron-injection yields constitute a significant mechanism for diminution of light-to-electrical energy conversion efficiencies in many dye-sensitized solar cells (DSCs). For TiO2-based DSCs prepared with an archetypal donor-acceptor organic dye, (E)-2-cyano-3-(5′-(5′′-(p-(diphenylamino)phenyl)-thiophen-2′′-yl)thiophen-2′-yl)acrylic acid (OrgD), we find, in part via ultrafast spectroscopy measurements, that postdye-adsorption atomic layer deposition (ALD) of ultrathin layers of either TiO2 or Al2O3 effectively reverses residual aggregation. Notably, the ALD treatment is significantly more effective than the widely used aggregation-inhibiting coadsorbent, chenodeoxycholic acid. Primarily because of reversal of OrgD aggregation, and resulting improved injection yields, ALD post-treatment engenders a 30+% increase in overall energy conversion efficiency. A secondary contributor to increased currents and efficiencies is an ALD-induced attenuation of the rate of interception of injected electrons, resulting in slightly more efficient charge collection.
AB - Dye aggregation and concomitant reduction of dye excited-state lifetimes and electron-injection yields constitute a significant mechanism for diminution of light-to-electrical energy conversion efficiencies in many dye-sensitized solar cells (DSCs). For TiO2-based DSCs prepared with an archetypal donor-acceptor organic dye, (E)-2-cyano-3-(5′-(5′′-(p-(diphenylamino)phenyl)-thiophen-2′′-yl)thiophen-2′-yl)acrylic acid (OrgD), we find, in part via ultrafast spectroscopy measurements, that postdye-adsorption atomic layer deposition (ALD) of ultrathin layers of either TiO2 or Al2O3 effectively reverses residual aggregation. Notably, the ALD treatment is significantly more effective than the widely used aggregation-inhibiting coadsorbent, chenodeoxycholic acid. Primarily because of reversal of OrgD aggregation, and resulting improved injection yields, ALD post-treatment engenders a 30+% increase in overall energy conversion efficiency. A secondary contributor to increased currents and efficiencies is an ALD-induced attenuation of the rate of interception of injected electrons, resulting in slightly more efficient charge collection.
KW - atomic layer deposition (ALD)
KW - dye aggregation
KW - dye-sensitized solar cells (DSCs)
KW - interfacial electron injection
KW - post-treatment
UR - http://www.scopus.com/inward/record.url?scp=84924561728&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84924561728&partnerID=8YFLogxK
U2 - 10.1021/am507405b
DO - 10.1021/am507405b
M3 - Article
AN - SCOPUS:84924561728
VL - 7
SP - 5150
EP - 5159
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
SN - 1944-8244
IS - 9
ER -