Electro-optical properties of CdS0.1Se0.9 nanocrystals

Nanocrytals of CdS0.1Se0.9 were fabricated by first annealing Cd, S, and Se-doped silicate glass at 480°C for 5 h and then annealing at 620°C for 8 or 16 h in an atmospheric environment. Electroabsorption (EA) spectra of the nanocrystals were measured at a frequency similar to the applied electric fields. Strong electro-optical signals (10−3) were observed in both resonant and nonresonant regions. The electro-optical signals in the resonant region were due to the quantum-confined Stark effects whereas those in the nonresonant region were due to the effects of external electric field on the change of the local field that resulted in the change of refractive index. The electro-optical signal amplitude in both resonant and nonresonant regions showed a quadratic dependence on the external electric fields. This suggested that the nanocrystals had the third-order nonlinear optical susceptibility.