Finding the Energy Gap of Ga_{1 –x}In_xAs p–n Junctions on a Metamorphic Buffer from the Photocurrent Spectrum

Abstract

A relationship has been established between the energy gap width of GaInAs p–n homojunctions and the saturation current. For this purpose, a method was suggested and substantiated for determining the energy gap width of a p–n junction from the spectrum of the photocurrent quantum efficiency. The method was applied to Ga_{1 –x}In_xAs p–n junctions grown by metal-organic vapor-phase epitaxy on metamorphic buffers. The difference between the energy gap width determined by using the suggested method and that found from the peak of the electroluminescence spectrum did not exceed 3 meV. It was found that the saturation current exponentially depends on the energy gap width, and this dependence is characterized by a current invariant.