SOLVE

This command solves transient PDEs associated with the fields in the structure. The description of the PDEs is found on the property lists associated with the fields (see math documentation ).

• HOURS
• MINUTES
• SECONDS
• TEMPERATURE
• TEMPFINAL
• SYSTEM

The following list itemizes the valid keywords and their meaning.

HOURS: [real]

MINUTES: [real]

SECONDS: [real]

total time is 3600*HOURS + 60*MINUTES + SECONDS. Timesteps which are printed out are in seconds.

TEMPERATURE: [real]

at which solution process is carried out, in degrees Celsius. This causes a variable T (absolute temperature = TEMPERATURE + 273.15) and a variable kT (where k is Boltzmann's constant normalized by electron charge) to be defined in the parser symbol table, for use in temperature dependent constants.

TEMPFINAL: [real]

the temperature is not constant, it is linearly ramped from TEMPERATURE to TEMPFINAL.

SYSTEM: [string]

system of equations to be solved is decided by comparing the name of the system with the fields in the structure. If no system is specified, the system of equations to be solved is taken from

library/physics/material/field/math.default

for each field in the structure. (Normally all fields will have a SeeAlso link to the same system; if not, two or more systems will be solved simultaneously, one for each independent system belonging to the fields present. Any field not having a PDE system defined will be ignored during the solution process). If a SYSTEM=xyz is given, the system is taken from

library/physics/material/field/math.xyz

If the given systemname ("default" if none given) does not solve for any of the fields in the structure, a warning will be printed:

No system has a pdeblock defined? steady_solve: bad setup. Quitting

Some systems are predefined, among them the following System Name Expected Fields Problem description

"default" for dopants standard fermi-level dependent diffusion for silicon doping

"default" for fields c1,c2,...cn simple reaction-diffusion system using reactions in ode.F coupled diffusion for TED "moment1" for dopants and simulation using one moment interstitials model of clusters nonlinear poisson equation for "newton0" for psi device simulation with flat fermi levels

"newton1e" for psi,electrons drift-diffusion model for electrons only

"newton1h" for psi,holes drift-diffusion model for holes only

"newton2" for psi,holes,electrons drift-diffusion model for 2 carriers