The current spreading in metal electrodes/pads and semitransparent ITO layers is considered in SpeCLED self-consistently. The heat transfer analysis coupled with the current-spreading problem provides the temperature distribution inside the LED chip. The heat generation inside the chip is found with account of the current density distribution obtained from the current-spreading problem. The temperature effect on the active region characteristics, as well as on the impurity ionization in thick semiconductor layers is considered in simulations.Files with results of computations generated by SpeCLED package can be used as input data for RATRO, a 3D ray-tracing simulator of the light extraction from the LED chip.
-Band diagram is calculated by the Poisson equation
Two types of boundary conditions on the top contact
-Schottky barrier on the gate contact
-Band bending because of the surface trap levels on the intercontact surface
Calculation of key electrical properties of individual SLs involved in the structure
-Electronic structure: energy levels and wave functions of localized carrier states, parameters of minibands.
-Carrier concentration and impurity ionization.
-Electric field distribution
-Conductivity of SL
Simulation of the whole device at given bias by self-consistent solution of Poisson and Schrodinger equations coupled with carrier transport equations.
-Band diagram.
-Energy levels and wave functions of carrier states in each QW.
-Carrier concentrations and impurity ionization.
-Carrier fluxes and recombination rates.
-Emission spectrum.
-Current-voltage (I-V) characteristic can be calculated by series of computations.
Single computations at a given bias provide following characteristics:
-Current density, power, conversion efficiency;
-Band diagram, electric potential, electric field;
-Carrier and ionized impurity concentrations;
-Generation rate, recombination rates (different channels);
-Partial electron and hole current densities.
Single or multiple tunnel junctions can be simulated using theoretical predictions, semi-empirical models, or using measurement data.Series computations with varying bias can be used to obtain I-V characteristic, conversion efficiency, short-circuit current, open-circuit voltage, and fill factor. Series computations with varying excitation wavelength can be used to find spectral dependencies of IQE and EQE