pvdeg.letid.calc_dn

pvdeg.letid.calc_dn(tau, temperature, suns, jsc, wafer_thickness, s_rear, na=7.2e+21, xp=2.4e-07, e_mobility=0.15, nc=2.8e+25, nv=1.6e+25, e_g=1.79444e-19)

Return excess carrier concentration, i.e. “injection”, given lifetime, temperature, suns-equivalent applied injection, and cell parameters

Parameters:

• tau (numeric) – Carrier lifetime [us].

• temperature (numeric) – Cell temperature [K].

• suns (numeric) – Applied injection level of device in terms of “suns”, e.g. 1 for a device held at 1-sun Jsc current injection.

• jsc (numeric) – Short-circuit current density of the cell [mA/cm^2].

• wafer_thickness (numeric) – Wafer thickness [um].

• s_rear (numeric) – Rear surface recombination velocity [cm/s].

• na (numeric, default 7.2e21) – Doping density [m^-3].

• xp (numeric, default 0.00000024) – width of the depletion region [m]. Treated as fixed width, as it is very small compared to the bulk, so injection-dependent variations will have very small effects.

• e_mobility (numeric, default 0.15) – electron mobility [m^2/V-s].

• nc (numeric, default 2.8e25) – density of states of the conduction band [m^-3]

• nv (numeric, default 1.6e25) – density of states of the valence band [m^-3]

• e_g (numeric, default 1.79444e-19) – bandgap of silicon [J].

Returns:

dn (numeric) – excess carrier concentration [m^-3]