Minority-carrier MIS tunnel diode hydrogen sensors

✍ Scribed by V. Casey; J.B. McMonagle; B. O'Beirn

• Book ID: 103961380
• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 571 KB
• Volume: 30
• Category: Article
• ISSN: 0925-4005
• DOI: 10.1016/0925-4005(96)80054-2

✦ Synopsis

The electrical characteristics of Pd/LB film/n-Si tunnel diode hydrogen sensors containing one and three cadmium stearate Langmuir-Blodgett (LB) films are reported. The devices exhibit good rectification behaviour. However, the/V characteristics are complex and deviate considerably from ideal Schottky-barrier theory. The semiconductor surface appears to be inverted at zero bias. Saturation of the forward current is attributed to tunnel-limited transport in the case of single LB film devices and to insulator-limited conduction in the case of devices containing three LB films. Exposure to hydrogen causes pronounced degradation of the diode behaviour. In particular, the forward IV characteristic shows an lcx V 2 behaviour that cannot be satisfactorily explained. A plausible explanation, however, is offered for much of the observed data based upon a minority-carrier metal-insulator-semiconductor (MIS) tunnel diode model. However, the full range of behaviour observed cannot be treated adequately by any one theoretical model.