Effects of hydrogen passivation on near-infrared photodetection of n-type β-FeSi2/p-type si heterojunction photodiodes

Abstract

Hydrogen passivation was applied to the initial epitaxial growth of n-typeβ-FeSi2 thin films on p-type Si(111) substrates. Such passivation was applied at different gas inflow H2/Ar ratios ranging from 0 to 1.0. The photodetection performance of the photodiode fabricated at the optimum ratio of 0.2 was markedly improved as compared with those of the other samples. The quantum efficiency and detectivity were 2.08% and 5.40×109 cm Hz1=2/W-1, respectively. The enhanced photodetective performance should be mainly because dangling bonds that act as trap centers for photocarriers are effectively inactivated by the passivation. © 2012 The Japan Society of Applied Physics.