Inorganic flat detectors are known, which capture radiation by way of a photodetector and a scintillator and have increased sensitivity.
A-Si thin film transistors and a-Si PIN diodes are combined in commercially available flat detectors (for x-rays and other radiation). However these detectors are very complex in terms of manufacturing, in other words expensive, particularly as a result of the PIN diodes. Photodiodes based on organic semiconductor materials allow pixeled flat detectors with high external quantum efficiencies (50 to 85%) to be produced in the visible range of the spectrum. The thin organic film systems used here can be cost-efficiently manufactured using known manufacturing methods such as spin coating, doctor blade or printing processes and thus allow for cost savings, particularly for large-scale flat detectors. US 2003/0025084 for example discloses a promising application of such organic flat detectors as x-ray flat detectors e.g. within the field of medical imaging, since the light of a scintillator layer is typically detected here on relatively large surfaces of at least several centimeters.
US 2004/0135911 describes an inorganic flat detector, which discloses an inorganic p-i-n photodiode, for instance having a photoactive layer including amorphous selenium, which is connected to an amplifying circuit comprising several thin film transistors. The disadvantage here in addition to the use of expensive PIN diodes also consists in the need for an additional resistor Rload in each column.
A conventional flat detector based on PIN diodes is also known from the publication U.S. Pat. No. 6,600,160 B2, said flat detector also having, in addition to the significant disadvantage that photosensitive elements, in other words the PIN diodes, are uneconomical to manufacture, a circuit that only includes one amplifier, but however indicating an arrangement therefor in which an additional precise current source is needed for each column to be read out.