Angle of incidence | Spectrum | ||||||
Zenith, θ | ° | Isotropic | |||||
Azimuth φ | ° | ||||||
Side | Morphology | Periodicity | Angle (°) | Height (μm) | Width (μm) | |
Front | ||||||
Rear |
Layer | Thickness | Material | ||||
Surrounds | ||||||
Front film | nm | |||||
Substrate | μm | |||||
Rear film | nm | |||||
Rear reflector | R T A F_{Lamb} | |||||
Detached rear reflector | R_{r,int} F_{Lamb} | |||||
Minimum wavelength | nm | |
Maximum wavelength | nm | |
Wavelength interval | nm | |
Calculate gen profile | ||
Number of points | ||
Plot zeta | ||
Logarithmic profile | ||
First depth for log profile | μm |
Number of rays per run | ||
Max total rays | ||
Max total rays | ||
Max bounces per ray | ||
Max bounces per ray | ||
Intensity limit | % | |
Minimise error in J_{G} | ||
Significant figures |
Inputs have changed since last ray trace. Outputs below do not correspond to displayed inputs. Run ray tracing to update.
Mean ± 95% CI | Fraction of J_{inc} | ||||
(mA/cm^{2}) | (%) | ||||
Incident | J_{inc} | ± | |||
Lost | |||||
Reflected – external | J_{R,ext} | ± | |||
Reflected – escape | J_{R,esc} | ± | |||
Transmitted | J_{T} | ± | |||
Absorbed – front films | J_{A,F} | ± | |||
Absorbed – rear films | J_{A,R} | ± | |||
Absorbed – detached reflector | J_{A,det refl} | ± | |||
Photogeneration (absorbed) | J_{G} | ± | |||
Remainder | ± | ||||
Show spectrum (I) | |||
Show reflection (R) | |||
Show absorption (A) | |||
Show transmission (T) |
Show pathlength (Z) | |||
Show error | |||
Significant figures |
Wavelength | Intensity | Reflected | Absorbed | Transmitted | Path length | ||||
---|---|---|---|---|---|---|---|---|---|
(nm) | (W m^{-2} nm^{-1}) | (external) | (escape) | (substrate) | (front films) | (rear films) | enhancement | ||
This calculator determines the photogenerated current density in a solar cell or test structure under a chosen illumination spectrum. It can be used to assess or improve the optical properties of a cell or test structure.
The wafer optics calculator complements OPAL 2. Whilst OPAL 2 accurately calculates reflection, transmission and thin film absorption at a single surface, the Wafer Optics Calculator incorporates the effect of the wafer bulk and both of its surfaces. The Wafer Optics Calculator therefore permits the assessment of all optical losses and light trapping.
To simulate the optical behaviour of a wafer, the Wafer Optics Calculator must take a more computationally intensive approach than OPAL 2. Therefore, it is typically slower, and provides a less precise estimate of its outputs.
The wafer optics calculator combines Monte Carlo ray tracing with thin film optics. It calculates the photogenerated current in a wafer via the following algorithm:
To define the optical structure of a wafer, you may choose:
The Wafer Optics Calculator determines the optical losses and photogeneration in the wavelength range requested. It weights the magnitudes by the photon flux in the user-defined spectrum, then integrates over the wavelength, in order to calculate photon current density. The photogenerated current J_{G} in a wafer equates to the short circuit current that could be extracted from a perfect solar cell made from the wafer.
The Monte-Carlo algorithm employed by the Wafer Optics Calculator necessarily results in output uncertainties. These uncertainties are calculated by dividing the user-requested number of rays into several sub-simulations, then applying statistical analysis to the set of sub-simulations to arrive at a mean value and 95% confidence interval (about two standard deviations).
Uncertainties are largest when the number of rays simulated is small. It is possible to reduce the displayed uncertainty by choosing fewer wavelengths (increasing the wavelength interval or narrowing the range). Note, however, that the displayed uncertainty does not account for uncertainty caused by smoothing of the spectrum. The best way to reduce uncertainty is to increase the number of rays simulated. Unfortunately, this will inevitably increase computation time.
Note that in the current version, the uncertainties provided do not account for the impact of weakly absorbed well trapped rays that are not traced to their proper conclusion. To minimise adverse impacts on results, choose a low intensity limit and high maximum number of bounces."
Neither PV Lighthouse nor any person related to the compilation of this calculator make any warranty, expressed or implied, or assume any legal liability or responsibility for the accuracy, completeness or usefulness of any information disclosed or rendered by this calculator.
Comments? Bugs? Errors? Compliments?
Welcome to the wafer ray tracer
This calculator determines the photogenerated current density in a solar cell or test structure under a chosen illumination spectrum. It can be used to assess or improve the optical properties of a cell or test structure.
Please note: Internet Explorer does not properly support HTML5 and we are using that to download the data. If you want to download data please use Firefox or Chrome.
Neither PV Lighthouse nor any person related to the compilation of this calculator make any warranty, expressed or implied, or assume any legal liability or responsibility for the accuracy, completeness or usefulness of any information disclosed or rendered by this calculator.