Abstract
| Language | English |
|---|---|
| Pages | 18125-18133 |
| Number of pages | 9 |
| Journal | Journal of Physical Chemistry C |
| Volume | 113 |
| Issue number | 42 |
| DOIs | |
| Status | Published - 2009 |
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A comparison of different methods to determine the electron diffusion length in dye-sensitized solar cells. / Wang, H X; Peter, L A.
In: Journal of Physical Chemistry C, Vol. 113, No. 42, 2009, p. 18125-18133.Research output: Contribution to journal › Article
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TY - JOUR
T1 - A comparison of different methods to determine the electron diffusion length in dye-sensitized solar cells
AU - Wang, H X
AU - Peter, L A
PY - 2009
Y1 - 2009
N2 - A new steady-state method for determination of the electron diffusion length in dye-sensitized solar cells (DSCs) is described and illustrated with data obtained using cells containing three different types of electrolyte. The method is based on using near-IR absorbance methods to establish pairs of illumination intensity for which the total number of trapped electrons is the same at open circuit (where all electrons are lost by interfacial electron transfer) as at short circuit (where the majority of electrons are collected at the contact). Electron diffusion length values obtained by this method are compared with values derived by intensity-modulated methods and by impedance measurements under illumination. The results indicate that the values of electron diffusion length derived from the steady-state measurements are consistently lower than the values obtained by the non-steady-state methods. For all three electrolytes used in the study, the electron diffusion length was sufficiently high to guarantee electron collection efficiencies greater than 90%. Measurement of the trap distributions by near-IR absorption confirmed earlier observations of much higher electron trap densities for electrolytes containing Li+ ions. It is suggested that the electron trap distributions may not be intrinsic properties of the TiO2 nanoparticles but may be associated with electron-ion interactions.
AB - A new steady-state method for determination of the electron diffusion length in dye-sensitized solar cells (DSCs) is described and illustrated with data obtained using cells containing three different types of electrolyte. The method is based on using near-IR absorbance methods to establish pairs of illumination intensity for which the total number of trapped electrons is the same at open circuit (where all electrons are lost by interfacial electron transfer) as at short circuit (where the majority of electrons are collected at the contact). Electron diffusion length values obtained by this method are compared with values derived by intensity-modulated methods and by impedance measurements under illumination. The results indicate that the values of electron diffusion length derived from the steady-state measurements are consistently lower than the values obtained by the non-steady-state methods. For all three electrolytes used in the study, the electron diffusion length was sufficiently high to guarantee electron collection efficiencies greater than 90%. Measurement of the trap distributions by near-IR absorption confirmed earlier observations of much higher electron trap densities for electrolytes containing Li+ ions. It is suggested that the electron trap distributions may not be intrinsic properties of the TiO2 nanoparticles but may be associated with electron-ion interactions.
UR - http://www.scopus.com/inward/record.url?scp=70449586906&partnerID=8YFLogxK
UR - http://dx.doi.org/10.1021/jp906629t
U2 - 10.1021/jp906629t
DO - 10.1021/jp906629t
M3 - Article
VL - 113
SP - 18125
EP - 18133
JO - Journal of Physical Chemistry C
T2 - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 42
ER -