Determination of homogeneous and inhomogeneous broadening of electro-transmittance spectra of 11h exciton transition in InGaAs/InAlAs wide well at high electric field

The linewidths of 11h exciton transition of InGaAs/InAlAs wide well electro-transmittance spectra in the electric field range between 0 and 50 kV/cm were investigated. The linewidth can be decomposed into two components: inhomogeneous broadening (Gaussian profile) when temperature or interface roughness are dominated and homogeneous broadening (Lorentzian profile) when field ionization are important. An approximation to the convolution of a Lorentzian with a Gaussian function was used by taking a linear superposition of them in fitting electro-transmittance spectra. The parameters such as Gaussian broadening, total linewidths and the fraction of linear superposition were obtained from the fitting.