Blue and green electroluminescence from CdSe nanocrystal quantum-dot-quantum-wells

摘要: CdS/CdSe/ZnS quantum dot well (QDQW) nanocrystals were synthesized using the successive ion layer adsorption and reaction technique, their optical properties tuned by bandgap strain engineering. 3-monolayer (ML) CdSe QWs emitted blue photoluminescence at 467 nm with a spectral full-width-at-half-maximum of ∼30 nm. With 3 ML ZnS cladding layer, which also acts as passivating strain-compensating QDQWs acquired ∼35% yield QW emission. Blue green electroluminescence (EL) was obtained from QDQW light-emitting devices 3–4.5 QWs. It found that peak blueshifted, overall EL increasingly dominated defect state emission due to poor hole injection into QDQWs. The weak attributed strong field-induced charge separation resulting unique geometry, weakening oscillator strength transitions.