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Variable (Usual)

Dimension Meaning

AARC Absorption in the anti reflectance coating

Ai m2 Area of the region with emitter sheet resistance Rsheet,i

Amax m2 Not-metalized solar cell area

Ashaded m2 Area, which is additionally shaded

Atotal m2 Area of the whole solar cell or symmetry element

B cm3s-1 Coefficient of radiative recombination Cloc

Calibration factor needed for voltage calibration of PL-measurements

Cn m6/s Auger coefficient of the eeh process Cp m6/s Auger coefficient of the ehh process

df m Distance of two adjacent fingers on the front of a solar cell

Dit cm-2 Surface or interface state density

dn m Depth of one node in direction parallel to the fingers in a distributed circuit model

Dn cm2s-1 Diffusion coefficient of the electrons Dp cm2s-1 Diffusion coefficient of the holes

E V/m Electrical field

EC eV Lowest energy in the conduction band

EF eV Fermi level

Eg eV Energy of the band gap

Ei eV Energy of the fermi level in an intrinsic semiconductor at thermal equilibrium

Ek eV Energy of an electron with momentum k

Et eV Energy of a defect level

Etop eV Highest energy in the conduction band

Variable (Usual)

Dimension Meaning

EV eV Highest energy in the valence band

F(E) Fermi-Dirac distribution

fE Emitter correction factor to correct the effect of the emitter sheet resistance in a distributed circuit model fF

Correction factor to correct the effect of the resistance of the metal fingers in a distributed circuit model

G m-3s-1 Generation rate

Gill m-3s-1 Generation rate due to illumination Gn m-3s-1 Generation rate of electrons

Current, which passes the emitter resistance Rl* in between two adjacent fingers in a distributed circuit model of a solar cell

Iwith shading W/cm2

Illumination intensity used to generate the one sun short circuit current density in case of an additionally shaded area

Iwithout shading W/cm2

Illumination intensity used to generate the one sun short circuit current density without additionally shaded region (0.1 W/cm2)

J0 A/cm2 Generation current density (one diode model) J01 A/cm2 Generation current density in the neutral regions

(two diode model)

J02 A/cm2 Generation current density of the space charge region (two diode model)

Jill A/cm2 Additionally generated current density due to illumination

( )

V

Jlocalxsuns A/cm2 Local IV characteristic of a solar cell illuminated with an illumination intensity of x suns

Variable (Usual)

Dimension Meaning

Jmpp A/cm2 Current density at maximum power point Jn A/cm2 Current density of the electrons

Jp A/cm2 Current density of the holes Jsc A/cm2 Short circuit current density

xsuns local

Jsc, A/cm2 Local short circuit current density using an illumination intensity of x suns

sun

Jsc1 A/cm2 One sun short circuit current density

k kg m s-1 Momentum of an electron

kB Boltzmann constant, 1.380 6504×10-23 J/K [117]

lf cm Length of one finger on a solar cell

Ln cm Diffusion length of the electrons

Lh cm Diffusion length of the holes

m Ideality factor used in the one diode model

M

Part of the area of the solar cell, which is illuminated by the measurement spot and which is covered by the front metallization

MC Number of equivalent minima in the conduction band

mde kg Density-of-state effective mass for electrons mdh kg Density-of-state effective mass for holes

mhh* kg Effective mass of the heavy holes in the valence band mi* kg Effective mass of the electrons along the principal

axes of the ellipsoidal energy surfaces

mlh* kg Effective mass of the light holes in the valence band

mloc Local ideality factor

n cm-3 Electron density in the conduction band

Ν(Ε) cm-3 Density of states

n0 cm-3 Electron concentration in the conduction band at thermal equilibrium

n1 cm-3 SRH density for electrons

Variable (Usual)

Dimension Meaning

n1 Ideality factor of the first diode in the two diode model

n2 Ideality factor of the second diode in the two diode model

NA cm-3 Total concentration of acceptors

NA cm-3 Concentration of ionized acceptors

0

NA cm-3 Concentration of unionized acceptors Nb,Y

Number of nodes beneath the bus bar in direction parallel to the fingers in a distributed circuit model of a solar cell

Nbf,X

Number of nodes between two adjacent fingers in direction perpendicular to them in a distributed circuit model of a solar cell

NC cm-3 Effective density of states in the conduction band

ND cm-3 Total concentration of donors

+

ND cm-3 Concentration of ionized donors

0

ND cm-3 Concentration of unionized donors

Nf,X

Number of nodes beneath one grid finger in direction perpendicular to it in a distributed circuit model of a solar cell

Nf,Y

Number of nodes in the area of the grid fingers in direction parallel to them in a distributed circuit model of a solar cell

Nfront cm-3 Front surface doping concentration of an emitter

profile

ni cm-3 Intrinsic carrier concentration at thermal equilibrium nn cm-3 Electron concentration at the edge of the space charge

region in the n-doped material

np cm-3 Electron concentration at the edge of the space charge region in the p-doped material

nS cm-3 Concentration of electrons at the surface

Variable (Usual)

Dimension Meaning

Nt cm-3 Defect concentration

NV cm-3 Effective density of states in the valence band

p cm-3 Hole density in the valence band

p0 cm-3 Hole concentration in the valance band at thermal equilibrium

p1 cm-3 SRH density for holes

Pin W/cm2 Power density of an external illumination

corr suns

PLIVoc,0.2

PL-image obtained under Voc conditions and 0.2 suns equivalent illumination intensity, which is corrected for lifetime effects

corr onesun

PLIVext,

PL-image obtained applying an external voltage Vext and one sun equivalent illumination intensity, which is corrected for lifetime effects

PLIJsc,0.2suns

PL-image taken at Jsc-conditions and 0.2 suns equivalent illumination intensity

PLIJsc,onesun

PL-image taken at Jsc-conditions and one sun equivalent illumination intensity

PLIVoc,0.2suns

PL-image taken at Voc-conditions and 0.2 suns equivalent illumination intensity

PLIVext,onesun

PL-image taken at externally applied voltage Vext- and one sun equivalent illumination intensity

Ploss W Power loss in a solar cell due to (emitter) resistances pn cm-3 Hole concentration at the edge of the transition region

in the n-doped material

pp cm-3 Hole concentration at the edge of the transition region in the p-doped material

ps cm-3 Concentration of holes at the surface

q Elementary charge, 1.602 176 462(63)×10-19 C [117]

R s-1 cm-3 Total recombination rate

R0 s-1 cm-3 Recombination rate at thermal equilibrium RARC Reflectance of the anti reflectance coating