InAlAs avalanche photodiode with type-Ⅱ absorber for detection beyond 2 μm

摘要

In this work, we present the study on In_(0.53)Ga_(0.47)As/GaAs_(0.51)Sb_(0.49) type-Ⅱ heterojunction PIN diodes and Separate Absorption, Charge and Multiplication (SACM) APDs utilising In_(0.52)Al_(0.48)As as the multiplication layer and In_(0.53)Ga_(0.47)As/GaAs_(0.51)Sb_(0.49) type-Ⅱ heterostructures as the absorption layer. In_(0.52)Al_(0.48)As lattice matched to InP has been shown to have superior excess noise characteristics and multiplication with relatively low temperature dependence compared to InP. Furthermore, the type-Ⅱ staggered band line-up leads to a narrower effective bandgap of approximately 0.49 eV corresponding to the APD cut off wavelength of 2.4 μm. The device exhibited low dark current densities near breakdown. The device also exhibited multiplication in excess of 100 at 200 K.