Facile synthesized ZnO microcrystals for random microlasers and incandescent-type light sources†
In this context, well-crystallized ZnO microcrystals (MCs) with a well-faceted smooth surface were successfully synthesized. Due to the outstanding optical response and well-faceted crystallites, the as-synthesized low-dimensional crystals were employed to construct ultraviolet microsized random lasers. Additionally, the micro/nanocrystal being foreseen as key elements were deposited on the pre-synthesized Ga-doped ZnO microwires (ZnO/ZnO:Ga MWs) using a two-step vapor-transporting synthesis method. By adjusting the as-synthesized condition, the incorporation of ZnO MCs can be utilized to tailor the fundamental optical and electronic transport properties of the pre-synthesized MWs. In particular, a single ZnO/ZnO:Ga MW was selected to construct a typical incandescent light source, with the lighting being color-tuned in a wide spectral region. The intrinsic working principle of the color-tuning electroluminescence may be attributed to type-II energy band alignment towards the interface of ZnO/ZnO:Ga. Therefore, individual ZnO/ZnO:Ga MWs can endow a new sense of the oldest and simplest incandescent-type sources. It can be anticipated that the lighting features of ZnO MC sheathed ZnO:Ga MW radial structures are extremely attractive for potential applications in ZnO based optoelectronic devices, such as microsized diodes and lasers, waveguides, high gain photodetectors, etc.