Measurement of the barrier height of a multiple quantum barrier (MQB)

A method of using a light-emitting diode structure with two active regions to measure the excess barrier height induced by the inclusion of a multiple quantum barrier structure is outlined. For a multiple quantum barrier structure previously used in a visible laser device, the resultant increase in barrier height was found to be 26 meV. The effect of the first barrier thickness on the produced barrier height is also investigated. It was found that by optimizing this parameter, the induced barrier height could be increased to 55 meV. These results are compared with those predicted by theory, and certain discrepancies between them are discussed.<
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