CsCu(2)I(3) Nanocrystals: Growth and Structural Evolution for Tunable Light Emission

[Image: see text] CsCu(2)I(3) mixed with Cs(3)Cu(2)I(5) has shown potential applications as white-light-emitting materials, while their growth, structural evolution behaviors, and their impact on photoluminescence of CsCu(2)I(3) nanocrystals (NCs) are still not known. In this work, we investigated the growth and structural evolution of CsCu(2)I(3) nanocrystals with increasing reaction temperature. At low temperature and in the presence of a high dosage of oleic acid and oleylamine, Cs(3)Cu(2)I(5) nanoparticles, rather than CsCu(2)I(3) NCs, preferred to form in the hot-injection reaction system. Increasing the reaction temperature promoted the formation of CsCu(2)I(3) nanorods. Phase-pure CsCu(2)I(3) nanorods were steadily obtained at 180 °C. Structural evolution from less copper-containing NCs to copper-rich ones in the low-temperature reaction condition is highly related to the coordination of copper ions with OAm. More importantly, accompanying the growth of nanorods and structural evolution from Cu(3)Cs(2)I(5) to CsCu(2)I(3), the color of photoluminescence emission of NCs changed from blue to nearly white and to yellow, but their photoluminescence quantum yield decreased from 36.00 to 9.86%. The finding in this work would give a view to the structural evolution of copper-containing perovskite-like halides, being helpful for adjusting their photoluminescence in white LEDs.