Current Schottky barrier sensors

The contact leakage current for an ideal Schottky barrier is the saturation current J, which depends on the barrier height according to Eq. (9.14). Examples of the forward J-V characteristics of some p-4-n sensors are shown in Fig. 10.6 and compared with a palladium Schottky barrier sensor. The ideality factor of the p-i-n devices is... 

Light sensors made from a-Si H are either p-i-n or Schottky barrier structures. Unlike crystalline silicon, a p-n jimction is ineffective without the undoped layer, because of the high defect density in doped a-Si H. Illumination creates photoexcited carriers which move to the junction by diffusion or drift in the built-in potential of the depletion layer and are collected by the junction. A photovoltaic sensor (solar cell) operates without an externally applied voltage and collection of the carriers results from the internal field of the junction. When the sensor is operated with a reverse bias, the charge collection generally increases and the main role of the doped layers is to suppress the dark current. A Schottky device replaces the p-type layer with a metal which provides the built-in potential. 

Fig. 10.6. Examples of the forward bias current-voltage characteristics of p-i-n sensors, compared to a Schottky barrier device.

Korotcenkov s research results are well known in the study of Schottky barriers, MOS structures, native oxides, and photoreceivers based on III-V compounds. His current research interests, starting from 1995, include material sciences and surface science, focused on metal oxides and solid state gas sensor design. 

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