Fluorination-Enhanced Ambient Stability and Electronic Tolerance of Black Phosphorus Quantum Dots

Xian Tang; Hong Chen; Joice Sophia Ponraj; Sathish Chander Dhanabalan; Quanlan Xiao; Dianyuan Fan; Han Zhang

doi:10.1002/advs.201800420

Fluorination-Enhanced Ambient Stability and Electronic Tolerance of Black Phosphorus Quantum Dots

Adv Sci (Weinh). 2018 Jun 13;5(9):1800420. doi: 10.1002/advs.201800420. eCollection 2018 Sep.

Authors

Xian Tang^{1

2}, Hong Chen², Joice Sophia Ponraj³, Sathish Chander Dhanabalan¹, Quanlan Xiao¹, Dianyuan Fan¹, Han Zhang¹

Affiliations

¹ Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics Collaborative Innovation Center for Optoelectronic Science and Technology, and Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Optoelectronic Engineering Shenzhen University Shenzhen 518060 China.
² School of Materials Science and Energy Engineering Foshan University Foshan 528000 China.
³ Department of Nanoscience and Technology Bharathiar University Coimbatore 641046 India.

Abstract

The environmental instability and uneliminable electronic trap states in black phosphorus quantum dots (BPQDs) limit the optoelectronics and related applications of BPQDs. Here, fluorinated BPQDs (F-BPQDs) are successfully synthesized by using a facile electrochemical exfoliation and synchronous fluorination method. The F-BPQDs exhibit robust ambient stability and limited fluorination capability, showing a nonstoichiometric fluorination degree (D_F) maximum of ≈0.68. Density functional theory calculations confirm that due to the edge etching effect of fluorine adatoms, the simulated F-BPQDs become structurally unstable when D_F surpasses the limit. Furthermore, the trap states of BPQDs can be effectively eliminated via fluorination to obtain a coordination number of 3 or 5 for fluorinated and unfluorinated phosphorus atoms. The results reveal that the air-stable F-BPQDs exhibit fluorine defect-enhanced electronic tolerance, which is crucial for nanophotonics and nanoelectronics applications.

Keywords: defect tolerance; density functional theory (DFT) calculations; electrochemical exfoliation; fluorinated phosphorene quantum dots; trap states.