TY - JOUR
T1 - Vanadium oxide as new charge recombination blocking layer for high efficiency dye-sensitized solar cells
AU - Elbohy, Hytham
AU - Thapa, Amit
AU - Poudel, Prashant
AU - Adhikary, Nirmal
AU - Venkatesan, Swaminathan
AU - Qiao, Qiquan
N1 - Funding Information:
This study was partially supported by the US-Pakistan Joint Science and Technology, NSF/EPSCoR program (Grant no. 0903804 ) and by the State of South Dakota, NASA EPSCoR program (Grant no. NNX13AD31A ), SDBoR CRGP, and Egyptian government fellowship (Egyptian Missions sector, 2012) for Mr Elbohy.
PY - 2015/4/1
Y1 - 2015/4/1
N2 - Vanadium pentoxide (V2O5) was used as a novel blocking layer in dye-sensitized solar cells (DSCs), leading to a significant efficiency increase from 8.78% to 9.65%. The addition of V2O5 layer to nanocrystalline (nc)-TiO2 increased peak external quantum efficiency (EQE) from~80% to ~88-89%. Cyclic Voltammetry analysis indicated a positive shift of Fermi-level in case of TiO2/V2O5 based cells supported by an increase of its capacitance comparing to bare TiO2 based cells. Electrochemical impedance spectroscopy (EIS) results exhibited a ~5 times higher charge recombination resistance (RCT) in V2O5 layer modified DSCs than conventional cells, which indicated that back charge transfer from TiO2 to tri-iodide in the electrolyte was substantially suppressed. Transient photovoltage measurements on conventional and V2O5 layer modified cells were conducted and their decays were fitted to calculate the electron recombination lifetime (τn), which increased by a factor of ~3 in V2O5-based DSCs. This indicated that V2O5 significantly reduced the recombination rate at TiO2/electrolyte interface, further supporting that V2O5 functioned as a new effective surface passivation layer.
AB - Vanadium pentoxide (V2O5) was used as a novel blocking layer in dye-sensitized solar cells (DSCs), leading to a significant efficiency increase from 8.78% to 9.65%. The addition of V2O5 layer to nanocrystalline (nc)-TiO2 increased peak external quantum efficiency (EQE) from~80% to ~88-89%. Cyclic Voltammetry analysis indicated a positive shift of Fermi-level in case of TiO2/V2O5 based cells supported by an increase of its capacitance comparing to bare TiO2 based cells. Electrochemical impedance spectroscopy (EIS) results exhibited a ~5 times higher charge recombination resistance (RCT) in V2O5 layer modified DSCs than conventional cells, which indicated that back charge transfer from TiO2 to tri-iodide in the electrolyte was substantially suppressed. Transient photovoltage measurements on conventional and V2O5 layer modified cells were conducted and their decays were fitted to calculate the electron recombination lifetime (τn), which increased by a factor of ~3 in V2O5-based DSCs. This indicated that V2O5 significantly reduced the recombination rate at TiO2/electrolyte interface, further supporting that V2O5 functioned as a new effective surface passivation layer.
KW - Charge recombination blocking layer
KW - Dye-sensitized solar cells
KW - Vanadium oxide
UR - http://www.scopus.com/inward/record.url?scp=84926010831&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84926010831&partnerID=8YFLogxK
U2 - 10.1016/j.nanoen.2014.09.008
DO - 10.1016/j.nanoen.2014.09.008
M3 - Article
AN - SCOPUS:84926010831
SN - 2211-2855
VL - 13
SP - 368
EP - 375
JO - Nano Energy
JF - Nano Energy
ER -