| 摘要 |
A photosensor for the detection of infrared radiation in the wavelength range of 1 to 1000 micrometers consists of a semiconductor substrate with a highly doped interaction volume for the incoming radiation. At the edge of this highly doped region, an extended gate electrode is placed consisting of a conducting material on top of an insulating layer. On the other side of the gate electrode, another highly doped semiconductor region is placed, acting as a charge collector. Through free carrier absorption in the interaction volume, incoming photons impart their energy on mobile charge carriers. In the case of free electrons, the gate electrode is biased slightly below the reset voltage of the interaction volume, so that the electrons carrying the additional energy of the absorbed photons can predominantly make the transition from the interaction volume across the gate electrode area to the charge collector volume, whose potential has been set sufficiently high so that the collected free electrons remain in this semiconductor region. The collected free charge carriers are electronically detected with known circuits for the measurement of electric current or charge packets. A multitude of such infrared photosensor devices can be arranged in one- or two-dimensional arrays to form line or image sensors. |
