Fractional Contributions of Defect-Originated Photoluminescence from CuInS2ZnS Coreshells for Hybrid White LEDs

Abstract EN

The wide optical tunability and broad spectral distribution of CuInS2/ZnS (CIS/ZnS) coreshells are key elements for developing the hybrid white light emitting diodes where the nanoparticles are stacked on the blue LEDs.

Two CIS/ZnS555 nm and CIS/ZnS665 nm coreshells are utilized for the hybrid white LED development.

The time-resolved spectroscopy of CIS/ZnS555 nm and CIS/ZnS665 nm reveals the correlation between the fast, intermediate, and slow decay components and the interface-trapped state and shallow- and deep-trapped states, although the fractional amplitudes of photoluminescence (PL) decay components are widely distributed throughout the entire spectra.

The temperature-resolved spectroscopy explains that the PL from deep-trapped donor-acceptor (DA) state has relatively large thermal quenching, due to the relative Coulomb interaction of DA pairs, compared to the thermal quenching of PL from interface defect state and shallow-trapped DA state.

A good spectral coupling between the blue diode excitation and the PL from CIS/ZnS leads to the realization of hybrid white LEDs.