Scattering spectra semiconductor

The excellent, high-resolution y- and X-ray spectra which can be obtained from semiconductor detectors make the detectors very important in modern instruments. A typical spectrum is shown in Figure 10.11(b) which may be compared with the much broader peaks from a scintillation detector (Figure 10.11(a)). The spectra are not immune from the problem of Compton scattering (p. 461) but a good quality modem detector will have a photopeak to Compton peak ratio of 50 1 or better. Computer-aided spectrum analysis also serves to reduce the interference from the Compton effect. 

It was not until the development of Fourier transform infrared (FTIR) spectrometers (see Section 3.3.3.2) that the possibility of using an infrared laser routinely was opened up. The intensity advantage of an infrared interferometer, with which a single spectrum can be obtained very rapidly and then many spectra co-added, coupled with the development of more sensitive Ge and InGaAs semiconductor infrared detectors, more than compensate for the loss of scattering intensity in the infrared region. 

Low-Concentration Systems For semiconductor particles, the absorption spectrum is changed only slightly compared with the bulk. The scattering losses, present even in the nonabsorbing region, have been studied in detail, in view of their waveguid-ing applications and account has been taken of the size dependence of the refractive index [3.71]. Some results are reproduced in Fig. 5.3-13. 

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