ABSTRACT
Disordered semiconductors are widely used as optical information storage and transmission devices as well as high-resolution photo-and electronic resists (Fig. 6.1). Optital information storage and transmission devices
Figure 6.1 Optical information storage and transmission on the base of disordered semiconductors (ChGS is chalcogenide glassy semiconductors). There are four different groups of optical information recording methods. All methods are based on creating the image on the surface of a semiconductor layer. The difference in the methods is in how
this image is recorded. The first group includes methods based on representation by electrical charge distribution on the surface of the semiconductor layer. The second group includes methods based on representation of the image by inducing structural changes in the non-crystalline phase under light exposure, leading to local changes in the material’s optical and chemical properties. The third group includes methods based on representation of the image by inducing interaction between chalcogenide glassy semiconductor and metal under light exposure, leading to local changes in the material’s optical and chemical properties, similar to group two described above. Last, but not the least, the fourth group includes methods of representation using light-induced first-kind phase transitions. These include local crystallization of non-crystalline phase or local amorphization of crystalline phase or local material evaporation under light irradiation. While all these methods and optical recording devices based on disordered semiconductors are characterized by reusability, real-time recording, and high resolution, they are also marked with relatively low photosensitivity (Table 6.1).
