Semiconductor Module

New App: Wavelength Tunable LED

The new Wavelength Tunable LED app simulates the emission properties of a GaN-based light emitting diode (LED) device. The device has a double heterostructure design with an optically active InGaN layer placed between two layers of GaN. The indium composition of the InGaN layer can be varied in order to control the emission wavelength. The device current, intensity, and efficiency are all calculated, either for a single voltage or as a function of voltage over a user-defined range. The emission spectrum is calculated and when the peak emission falls within the viable range, the corresponding RGB value is computed displaying the emission color.

Wavelength Tunable LED app screenshot showing the emission spectrum and color after a successful simulation. Wavelength Tunable LED app screenshot showing the emission spectrum and color after a successful simulation.

Wavelength Tunable LED app screenshot showing the emission spectrum and color after a successful simulation.

Indirect Optical Transitions

Optical absorption in silicon and other indirect band-gap materials can now be modeled using the new Indirect Optical Transition feature. The photogeneration rate in silicon can be calculated automatically using an empirical model – making it quick and convenient to simulate silicon photovoltaic devices. Alternatively, for other materials, a user-defined option enables the photogeneration rate to be specified using either the refractive index or a value for the absorption coefficient. This Indirect Optical Transition feature may be used as a standalone feature within the Semiconductor interface or coupled with the Electromagnetic Waves, Frequency Domain or Electromagnetic Waves, Beam Envelopes interfaces (requires the Wave Optics Module).

(a) The main settings for Indirect Optical Transitions. There are two options in the Transitions model list: Empirical silicon absorption (Green and Keeves) and User-defined absorption. The empirical model requires no additional inputs if the electromagnetic field is being computed in an Electromagnetic Waves interface. (a) The main settings for Indirect Optical Transitions. There are two options in the Transitions model list: Empirical silicon absorption (Green and Keeves) and User-defined absorption. The empirical model requires no additional inputs if the electromagnetic field is being computed in an Electromagnetic Waves interface.

(a) The main settings for Indirect Optical Transitions. There are two options in the Transitions model list: Empirical silicon absorption (Green and Keeves) and User-defined absorption. The empirical model requires no additional inputs if the electromagnetic field is being computed in an Electromagnetic Waves interface.

Diamond Material Added to Semiconductors Material Library

Diamond is now available as a material within the Semiconductors Material Library.

Postprocessing Variables Improved for Spontaneous Emission

New postprocessing variables have been added, enabling the spontaneous emission spectrum to be plotted as a function of photon energy, wavelength, and frequency. Additionally, it is now possible to directly access the photon energy, wavelength, and frequency variables throughout the extra dimension that is added by the optical transitions feature, where previously these quantities needed to be calculated using an expression in terms of the angular frequency.