Hydrogen gas sensor based on NiO decorated macroporous silicon (MPS) heterojunction

Abstract

Abstract A highly sensitive hydrogen gas sensor operating at room temperature made of macroporous silicon (MPS) coated with a thin NiO film was realized. Macroporous silicon (MPS) layer was shaped by electrochemical anodization on an n-type Si surface. Thereafter, p-type NiO film was deposited onto the MPS surface by electrodeposition method. The morphology of the NiO/MPS sample was characterized by scanning electron microscopy (SEM). Al electrical contacts for further measurements were deposited onto the structure NiO/MPS by evaporation technique under vacuum. Gas sensing performances were measured to various H2 concentrations ranging from 122 to 1342 ppm at room temperature. The results showed that electrical behaviour of synthesized NiO/MPS sensor is similar to that of diode which can be used to detect H2 gas at low concentrations which reveal high sensitivity, fast response and recovery times working at room temperature.