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)