Organic shell engineering of CsPbBr3 perovskite quantum dots for efficient textile-based photodetectors

Abstract

Lead halide perovskite quantum dots (QDs) have emerged as next-generation materials for photodetectors (PDs). It is well known that conventional alkyl long-chain ligands show weak binding on the surface of the QD core, leading to low stability and poor charge transfer. Herein, we explore the effect of partial replacing of alkyl long-chain ligands with aromatic short-chain ligands, namely phenylethylamine (PEA) and trans-cinnamic acid (TCA), on the performance of CsPbBr₃ QDs-based PD deposited on textile. The planar-type PDs with optimum PEA (L-type) and TCA (X-type) ligand doping concentration show improved performance compared to the control device due to the combined effect of enhanced conductivity and photoluminescence lifetime, lower surface defect centres, and reduced non-radiative recombination. Notably, PEA-treated CsPbBr₃ QDs-based PD shows the best photodetection properties of blue light (448 nm) at 10 V with a peak responsivity of 149 mA W⁻¹ and EQE of 41.3%, which is almost 20 times higher than those of the control device and 3 times higher than the TCA-treated CsPbBr₃ QDs based device. In addition, this device reveals excellent mechanical and operational stability. These results pave the way for designing flexible and wearable perovskite QDs-based optoelectronic devices, which may find potential applications in future optoelectronic devices.