High-speed colour-converting photodetector with all-inorganic CsPbBr3 perovskite nanocrystals for ultraviolet light communication

• 来源期刊: 光：科学与应用（英文版）
• 年，卷（期）: 2019,（5）
• 页码范围: 881-892
• 页数: 12页
• 语种: 英文

摘要

Optical wireless communication (OWC) using the ultra-broad spectrum of the visible-to-ultraviolet (UV) wavelength region remains a vital field of research for mitigating the saturated bandwidth of radio-frequency (RF) communication.However,the lack of an efficient UV photodetection methodology hinders the development of UV-based communication.The key technological impediment is related to the low UV-photon absorption in existing silicon photodetectors,which offer low-cost and mature platforms.To address this technology gap,we report a hybrid Sibased photodetection scheme by incorporating CsPbBr3 perovskite nanocrystals (NCs) with a high photoluminescence quantum yield (PLQY) and a fast photoluminescence (PL) decay time as a UV-to-visible colourconverting layer for high-speed solar-blind UV communication.The facile formation of drop-cast CsPbBr3 perovskite NCs leads to a high PLQY of up to ～73％ and strong absorption in the UV region.With the addition of the NC layer,a nearly threefold improvement in the responsivity and an increase of ～25％ in the external quantum efficiency (EQE) of the solar-blind region compared to a commercial silicon-based photodetector were observed.Moreover,timeresolved photoluminescence measurements demonstrated a decay time of 4.5 ns under a 372-nm UV excitation source,thus elucidating the potential of this layer as a fast colour-converting layer.A high data rate of up to 34 Mbps in solar-blind communication was achieved using the hybrid CsPbBr3-silicon photodetection scheme in conjunction with a 278-nm UVC light-emitting diode (LED).These findings demonstrate the feasibility of an integrated high-speed photoreceiver design of a composition-tuneable perovskite-based phosphor and a low-cost silicon-based photodetector for UV communication.