A gold/organic semiconductor diode for ppm-level humidity sensing

Client: K. N. Toosi University of Technology

Date: 2011-2015

Director project: Prof. Faramarz Hossein-Babaei

Project type: Laboratory implementation

Project collaborator: Dr. Pejman Shabani

Summary of project:

Measuring humidity in ppm level is of major technological importance, particularly in petrochemical plants where the activity of nanoporous catalysts determines the process progress rates, and also in low-loss optical fiber production units where hygrometry at extremely low humidity levels in air, vacuum, and inert gas backgrounds is a vital necessity. In this project, a novel electronic humidity sensor is fabricated by depositing gold nanolayers on an air-stable hydrophobic organic semiconductor, oxidized poly[2-methoxy-5-(2-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV). The device demonstrates high sensitivity at H2O concentrations as low as ∼1 ppm in air, vacuum and inert backgrounds. The presence of gases such as CO2 and H2 in substantial concentrations and oxygen partial pressure variations in air do not interfere with the sensing process.  The device is affordable and easy to fabricate in a wide range of sizes and shapes and is anticipated to find a variety of applications in different branches of science and technology.