Highly Emissive Lanthanide-Based 0D Metal Halide Nanocrystals for Efficient Ultraviolet Photodetector

Recently, lanthanide-based 0D metal halides have attracted considerable attention for their applications in X-ray imaging, light-emitting diodes (LEDs), sensors, and photodetectors. Herein, lead-free 0D gadolinium-alloyed cesium cerium chloride (Gd3+-alloyed Cs3CeCl6) nanocrystals (NCs) are introduced as promising materials for optoelectronic application owing to their unique optical properties. The incorporation of Gd3+ in Cs3CeCl6 (CCC) NCs is proposed to increase the photoluminescence quantum yield (PLQY) from 57% to 96%, along with significantly enhanced phase and chemical stability. The structural analysis is performed by density functional theory (DFT) to confirm the effect of Gd3+ in Cs3Ce1-xGdxCl6 (CCGC) alloy system. Moreover, the CCGC NCs are applied as the active layer in UVPDs with different Gd3+ concentration. The excellent device performance is shown at 20% of Gd3+ in CCGC NCs with high detectivity (7.938 x 1011 Jones) and responsivity (0.195 A W-1) at -0.1 V at 310 nm. This study paves the way for the development of lanthanide-based metal halide NCs for next-generation UVPDs and other optoelectronic applications. Cs3CeCl6 (CCC) nanocrystals (NCs) possess fascinating optical properties due to their f-d coupling of Ce3+ ions. The incorporation of Gd3+ in CCC NCs can be a facile method to enhance photoluminescence quantum yield (PLQY) up to almost unity (96%) as well as the phase stability. This Cs3Ce1-xGdxCl6 alloyed NCs exhibits efficient device performance as a UV-light absorbing layer for photodetector with detectivity (7.938 x 1011 Jones) and responsivity (0.195 A W-1) at -0.1 V bias at 310 nm. image