The hetrojunction amorphous n+(a-Si)/n-i-p(a-SiC)/i-n+(a-Si) phototransistor with high gain (&#8764;40) and high speed (&#8764;10&#181;s)
In this report, a hetrojunction amorphous Si-SiC barrier transistor (a-HJBT) was successfully fabricated which revealed high gain (∼40) and high speed (∼10µs). The homojunction amorphous silicon bulk barrier phototransistor has been reported to be a high gain (∼12) and high speed (∼30µs) photosensing device. In this report, a significant improvement has been achieved by making a hetrojunction structure between the emitter and the base by a structure of n<sup>+</sup>(Si)/n-i-δp<sup>+</sup>(SiC) which is in contact with the i-n<sup>+</sup>(Si) collector layers. The structure was successfully made by plasma enhanced chemical vapor deposition (PECVD) on a glass substrate.
Amorphous silicon bulk barrier phototransistor with Schottky barrier emitter
An amorphous silicon indium tin oxide/n+‐i‐δ( p+)i/Al Schottky barrier phototransistor was fabricated on a glass substrate, where δ( p+) is the thin (200 A) p+ base. The operation of the transistor is similar to that of an n+‐i‐δ( p+)i‐n+ amorphous silicon bulk barrier phototransistor. Photogenerated holes are accumulated at the thin base region (barrier valley) and induce a large number of electrons injected from the Schottky barrier due to the hole induced barrier lowering. Varying the emitter and collector i‐layer thickness produced different current gains in which a maximum value of 5.6 is obtained for the 300‐A emitter i‐layer/p+/3000‐A collector i‐layer structure under an input red light intensity of 7.5 mW/cm2.
Strategies for glass based photonic system integration
There is a clear tendency to integrate more and more opto-electronic and micro-optical components like optical fibers, laser diodes, modulators, isolators, beam-splitting components and micro lenses in also increasingly dense and complex assemblies. The paper will discuss thin glass as a very promising base material for that kind of photonic packaging on interposer and board level including optical interconnection using fibers.