JV editor (Steady state simulation editor)

1. Inputs

If you click the JV editor icon in the simulation editors ribbon (??), the JV editor window will open (??). The JV editor is used to configure steady-state current–voltage simulations. It applies a voltage ramp from a defined start voltage to a stop voltage, regardless of whether the device is a solar cell, an OFET, or another structure.

Simulation editors ribbon with the JV editor icon highlighted. — Opening the JV editor from the simulation editors ribbon.

You can set the start voltage, stop voltage, and step size. The JV voltage step multiplier scales the step size after each increment. The default is 1.0 (no growth). Setting this multiplier slightly above 1.0 can reduce the number of steps and speed up the simulation, but values much greater than 1.05 may cause convergence issues.

JV editor window with fields for start/stop voltage, step, step multiplier, external voltage as stop, and output controls. — JV editor window for configuring steady-state current–voltage simulations.

Parameter	Description
`Start voltage`	Beginning bias of the voltage ramp (V).
`Stop voltage`	Final bias of the voltage ramp (V).
`Voltage step`	Increment between successive bias points (V).
`JV voltage step multiplier`	Scales the step size after each point. Values > 1 increase the step as the sweep progresses (useful for large ranges); very large values may affect convergence.
`Use external voltage as stop`	Chooses the stopping criterion. When On, uses the external device voltage (after series/shunt resistance). When Off, uses the internal diode voltage.
`Maximum current density`	Terminates the sweep when current density reaches this threshold (A·m⁻²).
`Single point`	Computes a single operating point instead of a full JV sweep.
`JV curve photon generation efficiency`	Multiplier applied to the optical generation rate; can account for geminate recombination.
`Charge carrier generation model`	Selects the optical solver (e.g., Transfer Matrix, Ray Tracing).
`Smooth the EQE spectra`	Applies smoothing to EQE before use (used in certain 2D OFET simulations).
`Output verbosity to disk`	Controls snapshot writing (bands, carriers, generation rates). Write nothing, key results only, everything, or everything every nth step.
`Dump trap distribution`	Writes trap density-of-states profile to disk.
`Save parameter sweeps`	Saves summary metrics (average recombination, carrier densities, trapped carriers) in the `sweep` directory.

2. Outputs

Simulation files

Files produced by the JV simulation
File name	Description	Notes
`charge.dat`	Charge density vs. voltage
`jv.dat`	Current–voltage curve
`k.csv`	Recombination constant k
`sim_info.dat`	Simulation summary (calculated \(V_{oc}\), \(J_{sc}\), etc.); see §4.1.4

Simulation directories

Directories written by the JV simulation
Directory	Description	Notes
`snapshots/`	Position-dependent data per simulation step for key device parameters (e.g., conduction band, valence band, potential, carrier densities, generation and recombination rates).
`sweep/`	Spatially integrated (device-averaged) metrics as a function of simulation step (e.g., total/average recombination rate, average carrier density, trapped carrier density).

These outputs can be enabled by adjusting Output verbosity to disk (and, for aggregated metrics, enabling Save parameter sweeps) in the simulation editor.

sim_info.dat

This is a json file containing all key simulation metrics such as \(J_{sc}\), \(V_{oc}\), and example sim_info.dat file is given below:

Symbol	JSON token	Meaning	Units
\(FF\)	ff	Fill factor	au
\(PCE\)	pce	Power conversion efficiency	%
\(P_{max}\)	P_max	Power at maximum power point	W
\(V_{oc}\)	V_oc	Open-circuit voltage	V
\(voc_{R}\)	voc_R	Recombination rate at \(P_{max}\)
\(jv_{voc}\)	jv_voc	JV data point at \(V_{oc}\)
\(jv_{pmax}\)	jv_pmax	JV data point at \(P_{max}\)
\(voc_{nt}\)	voc_nt	Trapped electron density at \(V_{oc}\)	m\(^{-3}\)
\(voc_{pt}\)	voc_pt	Trapped hole density at \(V_{oc}\)	m\(^{-3}\)
\(voc_{nf}\)	voc_nf	Free electron density at \(V_{oc}\)	m\(^{-3}\)
\(voc_{pf}\)	voc_pf	Free hole density at \(V_{oc}\)	m\(^{-3}\)
\(J_{sc}\)	J_sc	Short-circuit current density	A m\(^{-2}\)
\(jv_{jsc}\)	jv_jsc	Average charge density at \(J_{sc}\)	m\(^{-3}\)
\(jv_{vbi}\)	jv_vbi	Built-in voltage	V
\(jv_{gen}\)	jv_gen	Average generation rate
\(voc_{np}\)	voc_np	Carrier density product at \(V_{oc}\)
\(j_{pmax}\)	j_pmax	Current at \(P_{max}\)	A m\(^{-2}\)
\(v_{pmax}\)	v_pmax	Voltage at \(P_{max}\)	V

Symbol	JSON token	Meaning	Units	Equ.
\(\mu_{jsc}\)	mu_jsc	Avg. mobility at \(J_{sc}\)	m\(^2\) V\(^{-1}\) s\(^{-1}\)
\(\mu^{geom}_{jsc}\)	mu_geom_jsc	Geom. avg. mobility at \(J_{sc}\)	m\(^2\) V\(^{-1}\) s\(^{-1}\)
\(\mu^{geom\_micro}_{jsc}\)	mu_geom_micro_jsc	Geom. micro avg. mobility at \(J_{sc}\)	m\(^2\) V\(^{-1}\) s\(^{-1}\)
\(\mu_{voc}\)	mu_voc	Avg. mobility at \(V_{oc}\)	m\(^2\) V\(^{-1}\) s\(^{-1}\)
\(\mu^{geom}_{voc}\)	mu_geom_voc	Geom. avg. mobility at \(V_{oc}\)	m\(^2\) V\(^{-1}\) s\(^{-1}\)	\(\sqrt{\langle\mu_e\rangle \langle\mu_h\rangle}\)
\(\mu^{geom\_avg}_{voc}\)	mu_geom_micro_voc	Geom. micro avg. mobility at \(V_{oc}\)	m\(^2\) V\(^{-1}\) s\(^{-1}\)	\(\langle\sqrt{\mu_e \mu_h}\rangle\)
\(\mu^e_{pmax}\)	mu_e_pmax	Avg. electron mobility at \(P_{max}\)	m\(^2\) V\(^{-1}\) s\(^{-1}\)
\(\mu^h_{pmax}\)	mu_h_pmax	Avg. hole mobility at \(P_{max}\)	m\(^2\) V\(^{-1}\) s\(^{-1}\)
\(\mu^{geom}_{pmax}\)	mu_geom_pmax	Geom. avg. mobility at \(P_{max}\)	m\(^2\) V\(^{-1}\) s\(^{-1}\)	\(\sqrt{\langle\mu_e\rangle \langle\mu_h\rangle}\)
\(\mu^{geom\_micro}_{pmax}\)	mu_geom_micro_pmax	Geom. micro avg. mobility at \(P_{max}\)	m\(^2\) V\(^{-1}\) s\(^{-1}\)	\(\langle\sqrt{\mu_e \mu_h}\rangle\)
\(\mu_{pmax}\)	mu_pmax	Avg. mobility at \(P_{max}\)	m\(^2\) V\(^{-1}\) s\(^{-1}\)

Symbol	JSON token	Meaning	Units	Equ.	Ref
\(\tau_{voc}\)	tau_voc	Recombination time at \(V_{oc}\)	s	\(R=(n-n_0)/\tau\)
\(\tau_{pmax}\)	tau_pmax	Recombination time at \(P_{max}\)	s	\(R=(n-n_0)/\tau\)
\(\tau^{all}_{voc}\)	tau_all_voc	Recombination time (all carriers) at \(V_{oc}\)	s	\(R=n/\tau\)
\(\tau^{all}_{pmax}\)	tau_all_pmax	Recombination time (all carriers) at \(P_{max}\)	s	\(R=n/\tau\)
\(\theta_{srh}\)	theta_srh	\(\theta_{SRH}\) Collection coefficient at \(P_{max}\)	au		p.100 5.2a