MEASUREMENT OF THE BARRIER HEIGHT OF A MULTIPLE-QUANTUM BARRIER (MQB)

A method of using a light-emitting diode structure with two active reg ions to measure the excess barrier height induced by the inclusion of a multiple quantum barrier structure is outlined. For a multiple quant um barrier structure, previously used in a visible laser device, the r esultant 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 ind uced barrier height could be increased to 55 meV. These results are co mpared with those predicted by theory, and certain discrepancies betwe en them are discussed.