Trends for Acceptor Dopants in Lead Halide Perovskites

Lead halide perovskites such as methylammonium lead iodideareattractive solar cell materials, and others such as cesium lead bromideare expected to be high-performing optoelectronic materials with potentialapplications including lighting, displays, and quantum information.All of these applications will benefit from having fully controlledelectrical conductivity, but it has proven difficult to achieve highhole concentrations in these materials via impurity doping. In thiswork, possible acceptor dopants for the halide perovskites (includingAg, Na, and Cu) are evaluated using first-principles calculationsbased on a hybrid functional with spin-orbit coupling. We assesswhich dopants can act as shallow acceptors on the proper substitutionalsite, whether other configurations of these impurities cause self-compensation,and whether native defects might ultimately compensate p-type dopingattempts. Among the dopants considered, sodium is consistently themost promising acceptor for achieving p-type conductivity in halideperovskites.