Defect passivation engineering of chalcogenide quantum dots via in situ fluorination treatment.

Efficient carrier transport through reducing the traps in chalcogenide quantum dots (QDs) is crucial for their application in optoelectronic devices. This study introduces an innovative in situ fluorination treatment to remove the whole-body traps of metal chalcogenide QDs, further accelerating the carrier transport process. The selected benzene carbonyl fluoride (BF) molecular additive can efficiently peel off the caused oxide traps and dangling bonds of chalcogenide QDs in real-time through the continuous release of the HF gas of BF decomposition. Experimental results revealed that the obtained chalcogenide QDs with in situ fluorination treatment can accelerate the charge extraction and hinder the charge recombination. Finally, two types of photo-electrical conversion devices, consisting of photodetectors and sensitized solar cells, are fabricated to reveal the advantages of in situ fluorination treatment of QDs. Our findings highlight in situ fluorination treatment towards chalcogenide QDs as a viable approach to reduce the traps of QDs and improve the performance in optoelectronic technologies, offering hope for the practical application of this technology in the near future.