Cost-effective silicon-quantum-dot white light-emitting devices with high performances

This work reports on cost-effective silicon-quantum-dot (Si QD) white light-emitting devices (WLEDs) with solid performances. Si QDs are made from trioxysilane (TES) whose cost is ∼1% that of hydrogen silsequioxane (HSQ), a usually adopted precursor of Si QDs. The WLED using TES-made Si QDs with HSQ being the host of Si QDs, retains the luminance similar to that of the conventional WLED that uses HSQ for both Si QDs and the host. Their external quantum efficiencies are also similar. To further promote the cost effectiveness, a SiO2 sol-gel termed SOG is synthesized to replace HSQ as the host of Si QDs. The cost of SOG is ∼0.1% that of HSQ. Such cost-effective HSQ-free WLEDs are found to perform fairly well as the conventional all-HSQ one. The cost-effective Si QD WLEDs are more available in practical applications in integrated Si photonics, Si display, and general lighting.