Changes of exciton reflectance spectra by an intense light beam (photoreflectance) are used to investigate electric fields on the free, unprepared crystal surface, originating from surface states. There are two types of photoreflectance spectra in CdS at 105 K, which are associated to different crystal properties A and B. The electric field increases in type A crystals and decreases in the case of type B crystals. This mechanism produces the main contribution to photoreflectance; the screening of the Coulomb interaction of the excitons by free electrons is negligible.
No takes yet. Share an insight, caveat, or question.
Lorenz Risch (1978) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: