Hydrogenated amorphous silicon speed sensor based on the flying spot technique

M. Vieira, A. Fantoni, A. Maçarico, F. Soares, G. Evans, R. Martins

Research output: Contribution to journalConference articlepeer-review

1 Citation (Scopus)


In the past we have developed a transient technique, called the Flying Spot Technique (FST). FST allows, not only to infer the ambipolar diffusion length but also the effective lifetime of the photogenerated carriers once the light spot velocity and geometry of the structure were known. In this paper, we propose to apply this technique backwards in order to detect the path and velocity of an object that is moving in the direction of a light source. The light reflected back from the object is analyzed through a p.i.n structure being the transient transverse photovoltage dependent on the movement of the object (position and velocity). Assuming that the transport properties of the material and the geometry of the device are known and using a triangulation method we show that it is possible to map the movement of the object. Details concerning material characterization, simulation and device geometry are presented.

Original languageEnglish
Pages (from-to)839-844
Number of pages6
JournalMRS Proceedings
Publication statusPublished - 1995
Event1995 MRS Spring Meeting - San Jose, United States
Duration: 6 Feb 19959 Feb 1995


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