Amorphous chalcogenide glasses are intrinsically metastable, highly photosensitive, and
therefore exhibit numerous light-induced effects upon bandgap and sub-bandgap illumination.
Depending on the pulse duration of the excitation laser, ChGs exhibit a series of light-induced effects
spanning over femtosecond to seconds time domain. For continuous wave (CW) illumination, the
effects are dominantly metastable in terms of photodarkening (PD) and photobleaching (PB) that
take place via homopolar to heteropolar bond conversion. On the other hand, under nanosecond
and ultrafast pulsed illumination, ChGs exhibit transient absorption (TA) that is instigated from the
transient bonding rearrangements through self-trapped exciton recombination. In the first part of the
review, we pay special attention to continuous wave light-induced PD and PB, while in the second
part we will focus on the TA and controlling such effects via internal and external parameters, e.g.,
chemical composition, temperature, sample history, etc.
History
Publication
Physics;3,pp. 253-274
Publisher
MDPI
Note
peer-reviewed
Other Funding information
Science and Engineering Research Board, Council of Scientific and Industrial Research, India