Solution-processed ternary compound semiconductor AgBiS2 colloidal quantum dots (CQDs) have emerged as promising light-absorbing materials due to their nontoxicity and high absorption coefficient (>106 cm-1). However, a rational strategy to passivate the facets of ternary compound CQDs and fabricate stable CQD inks has not yet been proposed. Chungbuk National University Han Seul Kim and Se-Woong Baek et al. proposed a ligand passivation strategy using a liquid-phase ligand exchange method.
A four-coordination system synthesis was employed to demonstrate multifaceted passivation on AgBiS2 CQDs and highly stable CQD inks. Density functional theory studies reveal secondary cation adsorption for silver halide passivation, demonstrating cooperative passivation of the ligand ensemble. This creates a low trap density in the CQD solid, increasing the power conversion efficiency of CQD solar cells by 53% to 8.1%.
In addition, this device has the fastest response time of 400 ns among all reported AgBiS2 devices, demonstrating its potential in the field of high-efficiency lead-free optoelectronics. The proposed non-toxic quantum dot passivation method is suitable for the development of next-generation lightweight, environmentally friendly and ultra-thin optoelectronic devices.
D. Kim, G. Cho, YH Kim, JH Kwon, Y. Oh, M. Yang, S. Jee, IS Lee, M.-J. Si, Y. Jung, HY Yang, Y. Ahn, B.- K. Kim, C. Kim, HS Kim, S.-W. Baek, Multi-Facet Passivation of Ternary Colloidal Quantum Dot Enabled by Quadruple-Ligand Ensemble toward Efficient Lead-Free Optoelectronics. Adv. Energy Mater. 2024, 2302579.
DOI: 10.1002/aenm.202302579
E-mail: info@chemborun.com
Tel: +86-574-87178138 
No. 1558, Jiangnan Road,, Ningbo, Zhejiang, China (Mainland)/31
