Preparation of nanostructured PbS thin films as sensing element for NO_2 gas

摘要

In this work, we demonstrate that semiconducting films of A_(Ⅳ)B_(Ⅵ) compounds, in particular, of nanostructured lead sulfide (PbS) which prepared by chemical bath deposition (CBD), can be used as a sensing element for nitrogen dioxide (NO_2) gas. The CBD method is versatile, simple in implementation and gives homogeneous semiconductor structures. We have prepared PbS nanocrystalline thin film at different reaction baths and temperatures. In the course of deposition, variable amounts of additives, such as organic substances among them, were introduced into the baths. The energy dispersive analysis (EDX) confirms the chemical composition of PbS films. A current-voltage (Ⅰ-Ⅴ) characterization of Pdc-PbS/a-SiC:H pSi(100)/Al Schottky diode structures were studied in the presence of NO_2 gas. The gas sensing behavior showed that the synthesized PbS nanocrystalline thin films were influenced by NO_2 gas at room temperature. The results can be used for developing an experimental sensing element based on chemically deposited nanostructured PbS films which can be applicable in gas sensors.