In general, the photosensitive area of a FFTCCD is completely covered with polysilicon gates for charge transportation. A front-illuminated (FI-CCD) device has no response in the UV spectrum, because the polysilicon gates absorb the input light. Absorption losses also occur in the visible spectrum causing a reduction in sensitivity. To enhance the UV response, a phosphorus coating (lumogen) can be applied. This is an organic material that degrades over time with bright UV exposure due to photodecomposition. With lumogen, the quantum efficiency (QE) at 250 nm is 7%, at 650 nm is about 40%. Ask for the S7010/S7011 series.

By flipping the CCD chip over and etching the back surface, absorption losses encountered in the FI-CCD are avoided and sensitivity greatly enhanced. The photo-generated carriers are collected in the bulk silicon and transported via polysilicon gates. This is called a back-thinned (BT-CCD) device. Hamamatsu№s unique treatment of the back surface yields a device with excellent QE in both UV and visible. The QE at 250 nm is 75% and 90% at 650 nm. Hamamatsu№s backside accumulation process not only enhances sensitivity but also produces superb stability against intense UV radiation. Ask for the S7030/S7031 series.

All of Hamamatsu№s CCDs can be integrated into a hermetic package with a single or two-stage thermoelectric cooler (TEC). Cooling the CCD reduces dark current and extends the dynamic range. With a single-state cooler, a delta T of 45ƒ C is possible. The C7021/C7041 are cooled multichannel detector heads for FI-CCD and BT-CCD, respectively. Hamamatsu also offers a complete evaluation kit that includes readout electronics, temperature controller, computer interface, and LabVIEW’ drivers. Ask for the HC-230 series.