Reduced interface roughness scattering in InGaAs/lnAIAs quantum cascade lasers grown on (411 )A InP substrates

摘要

Lattice-matched InGaAs-InAlAs quantum cascade lasers were prepared to compare differences between using a (411 )A InP substrate and a (100) InP substrate. The lasers grown on the (411)A substrate showed higher gain, lower threshold current density, higher slope efficiency, and twice the power efficiency compared to the otherwise-identical structure on the (100) substrate. This performance improvement is attributed to less interface roughness scattering at the heterointerfaces in the (411)A structure. The lower interface roughness scattering appears to result from the high-spatial frequency steps on the (411)A surface. Published by AIP Publishing.