Light receiving device

Abstract

A light receiving device having small dark current and capable of sensing light in the wavelength range of 2.0 μm to 3.0 μm with high sensitivity is provided. The light receiving device has an InP substrate, and a light receiving layer formed by alternately stacking a larger layer formed of GaInNAsSbP mixed crystal having nitrogen content of at most 5% in 5 group, larger lattice constant than that of InP and thickness between hc and 11hc, the critical thickness hc being determined as hc=b(1−ν cosα){log(hc/b)+1}/8πf(1+ν)cos λ and a smaller layer formed of GaInNAsSbP mixed crystal having nitrogen content of at most 5% in 5 group, smaller lattice constant than that of InP and thickness between hc and 11hc; absolute value of lattice mismatch of the larger layer and the smaller layer to the InP substrate is at least 0.5% and at most 5%; at least one of the layers has absorption edge wavelength of 2.0 μm to 3.0 μm; total thickness of respective layers is 2.0 μm to 4.0 μm; and thickness-weighted average lattice mismatch is set to be at most ±0.2%.