Electroluminescent Cu‐doped CdS Quantum Dots

Incorporating Cu-doped CdS quantum dots into a polymer host produces efficient light-emitting diodes. The Cu dopant creates a trap level that aligns with the valence band of the host, enabling the direct injection of holes into the quantum dots, which act as emitters. At low current densities, the luminance efficiency maximizes at 9 cd A−1, providing an external quantum efficiency of 5%.