Photoelectrochemical cells for hydrogen production from solar energy - Solar Energy Sciences and Engineering Applications - page 335

R i - Recombination rate of species i ,m − 3

·

s − 1

R E - Electrolyte resistance,
R Ohmic - Ohmic resistance,
T - Absolute temperature, K
t - Time, s
V OC - Open-circuit voltage, V
V loss - Ohmic voltage loss, V
V ( t ) - Voltage perturbation, V
V 0 - Amplitude of the voltage signal, V
W - Space charge thickness, m
x - Coordinate, m
z - Number of electrons transferred in the reaction
Z - Impedance,
Z C - Impedance of capacitor,
Z Imag - Imaginary Part of impedance,
Z Real - Real Part of impedance,
Z R - Impedance of a resistor R,
Z 0 - Ratio of the amplitude of the voltage signal and the amplitude of the
current collector

Greek symbols
α ( λ ) - Wavelength-dependent absorption coefficient, m − 1
β - Transfer coefficient
ε - Dielectric constant
ε 0 - Permittivity of free space, 8.85419 10 − 12 Fm − 1 ×

m − 1

ξ - Macroscopic electric field, V ·

φ - Phase angle, ◦
- Electrostatic potential, V
( x ) - Band Bending, V
FB - Flat Band potential, V
η - E Bias

V OC ,V
η a - Overpotential at the anode, V
η c - Overpotential at the cathode, V
η inj - Electron injection efficiency
η Ohmic - Ohmic overpotential, V
η Pt - Overpotential at Pt electrode (cathode), V
λ - Wavelength, m
µ i - Mobility of species i ,m 2

−

V − 1 s − 1

·

ρ ( x ) - Total charge density, m − 3
τ - Time constant of the reaction kinetics, s
τ n - Carrier lifetime, s
E F - Variation of the Fermi level potential, V
G - Free energy for the overall cell reaction, J
E - Electric potential of the reaction, V mol − 1

Superscripts
o - Standard