TCAD 2D numerical simulations for increasing efficiency of AlGaAs – GaAs Solar Cells

The performance of solar cells has improved quickly in recent years, the latest research focuses on thin cells, multijunction cells, solar cells of the group III-V compounds, Tandem cells, etc. In the present work, numerical simulations are developed, using SENTAURUS TCAD as a tool, in order to obtain a solar cell model based on Galium Arsenide (GaAs). This solar cell corresponds to the so-called "Thin Films" due to the fact that can make layers thinner than we would have if we work with conventional semiconductors, such as; Silicon or Germanium; thus opening the possibility of placing the cell as a top layer within a tandem solar cell configuration with compounds of group III-V. That is why two types of simulations are performed with respect to the contact of the rear contact; one corresponds to the cell with a lower contact equal to the length of the cell and the other with a small contact of 5 μm. In addition, the cell undergoes an optimization process by modifying the geometry and doping of the layers that comprise it, in order to improve its performance. To achieve this objective, the initial conditions and the appropriate simulation parameters must be determined, which have been selected and corroborated with the literature, allowing us to arrive at coherent results and optimal models of solar cell design through numerical simulations.

Impurity Determination in Group III–V Compounds

Methods for determination of trace and ultratrace impurities in group III–V compounds by emission spectroscopy have been investigated. Cleaning of organic and inorganic surface contaminants must be carefully carried out so that ultratrace determination is possible. The method takes advantage of preferential volatilization of group III-V compounds in a dc arc. Sequential exposure is used to improve signal-to-noise ratio. Concentrating the impurities in the electrode by arcing off some of the arsenic in gallium arsenide improves detection limits of relatively nonvolatile elements. The analytical results agree well with other techniques. Electrical properties of compounds also correlate well with the data. The coefficients of variation range from 20 to 40%.