N‐Type Colloidal‐Quantum‐Dot Solids for Photovoltaics

Abstract
N-type PbS colloidal-quantum-dot (CQD) films are fabricated using a controlled halide chemical treatment, applied in an inert processing ambient environment. The new materials exhibit a mobility of 0.1 cm2 V−1 s−1. The halogen ions serve both as a passivating agent and n-dope the films via substitution at surface chalcogen sites. The majority electron concentration across the range 1016 to 1018 cm−3 is varied systematically.