Advantage of tapered and graded AlGaN electron blocking layer in InGaN-based blue laser diodes

We investigate the advantage of tapered and graded AlGaN electron blocking layer (EBL) in InGaN-based blue laser diodes (LDs) theoretically by self-consistent Schrodinger-Poisson method together with transfer matrix method. Such optimized EBLs was found to suppress electron leakage current as well as enhance hole injection compared to their conventional counterpart. More uniform carrier distribution and thus uniform local gain profile is obtained in the active region of LDs with optimized EBLs. Slightly enhancement of optical confinement factor is also obtained. As a result, LDs with new EBL structure demonstrate better device performance with decrease of threshold current density and increase of light output power (? 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Copyright ? 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.EI3346-3491