Improvements of the modulation bandwidth and data rate of green-emitting CsPbBr 3 perovskite quantum dots for Gbps visible light communication

Abstract

CsPbBr 3 perovskite quantum dots (PQDs) as promising color conversion materials have been widely used in display and visible light communication (VLC), but most CsPbBr 3 PQDs for VLC are randomly selected without optimization. Thereby the exploration of fundamental experimental parameters of QDs is essential to better employ their performance advantages. Herein, we investigated the concentration and solvent effects on photoluminescence (PL) properties and communication performance of CsPbBr 3 PQDs. The PL, time-resolved PL characterization and communication measurements of CsPbBr 3 PQDs all exhibit concentration dependence, suggesting that there exists an optimum concentration to take advantages of performance merits. CsPbBr 3 PQDs with a concentration of 0.5 mg/ml show the shortest carrier lifetime and achieve the highest −3 dB bandwidth (168.03 MHz) as well as the highest data rate (660 Mbps) comparing to other concentrations. And in terms of the optimal concentration, we further explored the approach to improve the communication performance, investigating the effect of polarity solvent on the communication performance of CsPbBr 3 PQDs. Original 0.5 mg/ml CsPbBr 3 PQDs (1 ml) with 55 μ L ethanol added in obtain a higher −3 dB bandwidth of 363.68 MHz improved by ∼116.4% and a record data rate of 1.25 Gbps improved by ∼89.4% but weaker PL emission due to energy transfer. The energy transfer assisted improvement may open up a promising avenue to improve the communication performance of QDs, but more feasible energy transfer path needs to be explored to ensure the stability of QDs.