MOVPE growth for photodiodes in 2.5 µm region with InGaAs/GaAsSb type-II quantum wells

Low dark current photodiodes (PDs) in the short wavelength infrared (SWIR) region over 1.7 µm are expected to be used for many applications. InGaAs/GaAsSb type‐II quantum well (QW) structures are considered to be attractive material systems for realizing low dark current PDs, owing to lattice‐matching to InP substrates. In this report, we describe the successful operation of pin‐PDs with InGaAs/GaAsSb QWs with InP capping layers grown by metal‐organic vapor phase epitaxy (MOVPE). Distinct X‐ray diffraction satellite peaks and emissions from type‐II transition were observed. Electrical and optical characteristics of pin‐PDs, such as dependence of responsivity on the number of QWs, were investigated. Dark current was 9.0 µA/cm2 at 233 K and an external quantum efficiency (EQE) of 48% was obtained. These results indicate that it is possible to reduce the dark current of InGaAs/GaAsSb type‐II PDs by using the InP capping layers grown by MOVPE. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)