Electronic passivation of PbSe quantum dot solids by trimethylaluminum vapor dosing

[Display omitted] •Demonstrate the effect of trace defects on the electronic properties of PbSe solids.•Passivation of electronic defects using trimethyl aluminum (TMA).•10x improvement in on/off ratio and mobility of PbSe FET before and after TMA dosing. The inherent instability of PbSe quantum dot (QD) thin films in ambient atmospheric conditions presents a significant challenge to their use in devices. Using low-temperature scanning tunneling microscopy and scanning tunneling spectroscopy, the electronic passivation of epitaxially-fused PbSe QD superlattices (epi-SLs) by trimethylaluminum (TMA) vapor dosing was studied. TMA dosing immobilizes loosely bound mobile adsorbates and passivates states on the surface of the QDs. X-ray photoelectron spectra of QD films prepared by dip coating show an aluminum surface concentration of