Theoretical and Experimental Analysis of Leakage Current in InGaAsP BH Lasers with p-n-p-n Current Blocking Layers

The dependence of the leakage current in 1.3m InGaAsP buried heterostructure (BH) lasers with p-n-p-n current blocking layers on well number, mesa width, and carrier density has been analyzed using a two-dimensional device simulator and compared with the electroluminescence (EL) emitted from InP layers. The analysis of the minority carrier flow reveals that the electron current flowing through the p-n-p-n current blocking layers is the dominant component of the leakage current. The measured EL intensity has two peaks at both sides of the nblocking layer apart from the active layer. The EL intensity decreases with increasing well number and carrier density of the p-blocking layer, and increases with increasing mesa width. These results are consistent with the simulations.