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

Abstract

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 Si-based 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 colour-converting 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, time-resolved 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.

A Review on Practical Considerations and Solutions in Underwater Wireless Optical Communication

“…Figure 8 shows the small-signal frequency response of the photoreceiver with a 3-dB bandwidth of 91.91 MHz, which is relatively high compared to a conventional photodiode with the same detection area. The modulation bandwidth is primarily governed by the recombination lifetime of dye molecules [100], [104], and thus eliminating the need to balance the design trade-off between the detection area and the modulation bandwidth as in conventional photodiodes. Besides, with a conventional photodiode, although the angle of view can be improved by using additional receiver lenses, it is challenging to attain flexibility and omnidirectional detection.…”

“…Moreover, as compared to conventional photoreceivers based on Si-based photodiodes [46], [59], [67], [102] and solar panels [103], the use of scintillating fibers render large area detection while preserving the modulation bandwidth of the accompanying Si-based photodiode. This could also alleviate the costly and timely development path for a UV-based photoreceiver with a large detection area and high response speed [104]- [107]. Hence, the approach can accelerate the realization of UV-based NLOS communication modality to obviate the strict PAT requirements in UWOC.…”

2.4-Gbps Ultraviolet-C Solar-Blind Communication Based on Probabilistically Shaped DMT Modulation

“…Instead, diffuse-LOS and non-line-of-sight (NLOS) links can be established using UVC light. The aforementioned advantages, as well as the recent development in solid-state UVC light-emitting diodes (LEDs) and high-speed low-cost detectors [1], make UVC OWC a promising communication technology, but maintaining high speeds over practical distances has been a challenge. In [2], a 71megabit-per-second diffuse-LOS link was demonstrated based on a 294-nm LED operating in the ultraviolet-B (UVB) regime over a short distance of only 8 cm.…”

A Thermometer Based on Er‐Sensitized Phosphors Gd2(WO4)3:Er,Yb@SiO2 in Near‐Infrared and Visible Regions

“…Temperature‐sensing technology has played a key role in our life, which is used in almost every field such as chemistry, physics, and biology . Traditional temperature measurements have many defects.…”