Application Of Amorphous Silicon Research Articles

Amorphous Silicon as an Active Material in Optical Resonators

AbstractThe application of amorphous silicon as a thermo-optically active material in MEMS-based, tunable optical filters is presented. The thin film interference filter employs a solid-state silicon cavity and silicon-based distributed Bragg reflectors (DBR). Tuning is achieved by varying the the resonator's refractive index and thus its optical thickness through thermal modulation. The filter is configured as a membrane and operates up to a temperature of 450 °C. Such a filter is essential for monitoring and reconfiguration of optical data communication networks and is also applicable for chemical and gas sensing.

Novel Application of Amorphous Silicon in Electrostatic Loudspeakers

ABSTRACTA thin film of amorphous silicon (a-Si:H) has been developed for application as the charge retention layer in electrostatic loudspeakers. The vibrating diaphragm in this type of loudspeakers is usually coated with a thin film in order to assure homogeneous charge distribution across the surface. This thin film should be capable of maintaining a high surface charge density and possess a high lateral resistivity to prevent charge displacement. Furthermore, it should be mechanically stable, capable of accomodating mechanical deformation, and resistant against humidity. Conventionally, a graphite layer is used in these applications. However, the conventional layers are frequently unstable and suffer from charge displacement effects eventually leading to electric breakdown. Further requirements are that the film can be deposited continuously and homogeneously over large areas in excess of 1 m2 and that the deposition technique is compatible with the properties of the thin membrane. We investigated small-area prototypes of electrostatic loudspeakers with a-Si:H thin films deposited on polyimide substrates in the Utrecht deposition system, ASTER. Plasma-deposited amorphous silicon films fabricated under certain conditions are shown to meet all of the above requirements.

Doped amorphous silicon and its application in photovoltaic devices

The paper deals with the development of the new field of substitutionally doped amorphous semiconductors, and discusses the possible application of amorphous silicon in cheap large-area photovoltaic devices. Preparation and doping from the gas phase are described and the properties of an amorphous junction are discussed.

Doped amorphous silicon and its application in photovoltaic devices

The paper deals with the development of the new field of substitutionally doped amorphous semiconductors, and discusses the possible application of amorphous silicon in cheap large-area photovoltaic devices. Preparation and doping from the gas phase are described and the properties of an amorphous junction are discussed.