Energy Conversion and Storage
Simulation tools
Adept
ADEPT/F solves Poisson's equation coupled with the hole and electron continuity equations in one spatial dimension in compositionally nonuniform semiconductors. It was originally written to model solar cells fabricated from a wide variety of materials, including amorphous silicon, copper indium diselenide, and cadmium telluride. However, since material parameters (band gap, mobility, etc.) can be input by the user, devices fabricated from any material for which these parameters are known can be modeled. Dark I-V, light I-V, and spectral response of solar cells (or any two terminal device) can be computed. Plots of many internal parameters, such as carrier density, recombination, electric field, etc., can be plotted at any operating point.
Homostructures and heterostructures, both abrupt and graded, can be modeled. Solar cell material systems modeled include ZnO/CdS/CIS, ZnO/CdS/CIGS, CdS/CdTe, a-Si, Si, AlGaAs/GaAs, GaSb, InP, and several others.
MEEPPV
MEEPPV is a graphical user interface (GUI) based MEEP simulation tool, particularly for photovoltaic (PV) cells. It was developed for new and less users who are starting to use MEEP, as this tool requires a background understanding of Scheme language. MEEPPV now collects input from the Rappture interface, and uses it to create a Scheme control file to run MEEP on the back end as before. It outputs images of the PV cell structure being simulated; graphs of the transmission, reflection, and absorption; as well as an animation of the fields propagating through the PV cell.
PC1D
PC1D solves the fully coupled nonlinear equations for one-dimensional transport of electrons and holes in crystalline semiconductor devices, with emphasis on photovoltaic devices.
PV Analyzer
PV Analyzer is a tool for rapid data analysis and parameter extraction from solar cell measurements. Current version analyzes the dark current-voltage (IV) characteristics of solar cells to extract the diode and shunt current parameters. Large area solar cells have a significant parasitic conduction due to parallel shunt paths. In thin film cells in particular these shunt currents are non-ohmic and symmetric with voltage. This tool utilizes the symmetry of shunt current to separate the shunt and diode current components and then uses separate equations to fit the two current components. This separation and fitting method yields parameter values which are free from fluctuations due to parasitic and can be related to physical processes in the device. The tool can also analyze multiple IV data at once, and all the data as well as fit parameters can be downloaded as text files for further analysis.
Radiative Cooling Experiment
Simulate a passive radiative cooling solution implementation in an experimental setup.
Thermophotovoltaic (TPV) systems can generate electricity from high-temperature heat sources via thermal radiation. However, the intense heating of a photovoltaic (PV) cell can greatly reduce the overall efficiency of the system. Therefore, it is critical to develop techniques to keep the PV cells close to ambient temperature without consuming energy. Radiative cooling is a passive technique that dissipates heat into remote space via thermal radiation.
Radcool complements TPVexpt and predicts the performance of a radiative cooling system in general. The main design considerations of Radcool include: (1) the area ratio between the PV cell and the cooling emitter, and (2) the cooling emitter materials. The cooling performance is evaluated by equilibrium heat transfer analysis.
The radiative cooling technique is not limited to TPV systems; other potential applications include solar cell cooling, infrared detectors, and sensitive electronic devices that are used outdoors.