PbSe quantum dot field-effect transistors with air-stable electron mobilities above 7 cm2 V(-1) s(-1)

PbSe quantum dot (QD) field effect transistors (FETs) with air-stable electron mobilities above 7 cm(2) V(-1) s(-1) are made by infilling sulfide-capped QD films with amorphous alumina using low-temperature atomic layer deposition (ALD). This high mobility is achieved by combining strong electronic coupling (from the ultrasmall sulfide ligands) with passivation of surface states by the ALD coating. A series of control experiments rule out alternative explanations. Partial infilling tunes the electrical characteristics of the FETs.