Abstract: A photo-detecting device includes a first semiconductor layer with a first dopant, a light-absorbing layer, a second semiconductor layer, and a semiconductor contact layer. The second semiconductor layer is located on the first semiconductor layer and has a first region and a second region, the light absorbing layer is located between the first semiconductor layer and the second semiconductor layer and has a third region and a fourth region, the semiconductor contact layer contacts the first region. The first region includes a second dopant and a third dopant, the second region includes second dopant, and the third region includes third dopant. The semiconductor contact layer has a first thickness greater than 50 ? and smaller than 1000 ?.

Abstract: A movable air-permeable-tape dispenser. The dispenser includes a hollow cylindrical body provided with an axial long opening. A slide channel is parallelly adjacent to a first longitudinal edge of the long opening, and a stepped portion is parallelly adjacent to a second longitudinal edge of the opening. A cover is provided with a row of continuous teeth corresponding to the second longitudinal edge of the long opening and a shaft corresponding to the first longitudinal edge of the long opening. The shaft is fitted in the slide channel to enable the cover to pivotally turn about the shaft between a lifted position for a user to pull out via the long opening a length of air-permeable tape disposed in the cylindrical body.

Abstract: A movable air-permeable-tape dispenser includes a hollow cylindrical body provided with an axial long opening, a slide channel parallelly adjacent to a first longitudinal edge of the long opening, and a stepped portion parallelly adjacent to a second longitudinal edge of the long opening; and a cover provided with a row of continuous teeth corresponding to the second longitudinal edge of the long opening and a shaft corresponding to the first longitudinal edge of the long opening. The shaft is fitted in the slide channel to enable the cover to pivotally turn about the shaft between a lifted position for a user to pull out via the long opening a length of air-permeable tape disposed in the cylindrical body, and a closed position for the outward pulled tape to be cut off with the row of teeth on the cover.