Ag, Cd double gradient doping at front interface for high efficiency CZTSSe solar cells
Abstract
Kesterite Cu2ZnSn(S,Se)4 (CZTSSe) solar cells have attracted considerable attention in recent years, and considered to be potential alternative solutions to existing commercialized solar cells for future energy demands. However, poor-quality p-n junction causes severe carrier recombination at the front interface, resulting high open-circuit voltage deficit and unsatisfactory efficiency of CZTSSe solar cells. In this work, Ag,Cd double gradient doping was introduced to front interface for interface carrier recombination suppression. Benefited from the formed Ag,Cd double gradient, defect and/or defect cluster at front interface significantly reduced, thus evidently suppressing the carrier recombination at front interface. As a result, the power conversion efficiency (PCE) of champion device increased from 10.04?% (Reference) to 12.66?% (With Ag,Cd). This Ag,Cd double gradient architecture offers new ideas for improvement of high efficiency CZTSSe as well as other solar cells.