P‐Type Antimony Selenide via Lead Doping. Issue 7 (16th November 2021) - Huang, Menglin
Abstract : p‐type doping in antimony selenide (Sb2 Se3 ) is an important issue to improve its photovoltaic performance, because the as‐grown Sb2 Se3 usually shows weak p‐type conductivity and leads to low open‐circuit voltage. However, no effective p‐type doping strategy has been reported so far. Herein, combining theoretical calculation and experiment, it is demonstrated that lead doping can effectively enhance the p‐type conductivity because of the low formation energy of the substitutional acceptor PbSb with a (–/0) transition level of 0.15 eV. This is further validated by a conductivity measurement that observes a shallow acceptor level. As a result, a free hole carrier density as high as 10 16 cm −3 is achieved for the first time. Furthermore, theoretical analysis on defect densities related to experimentally characterized device performances after Pb doping is presented. The study provides a new p‐type doping strategy as well as the implicit defect physics, which can be useful for further improvement of Sb2 Se3 solar cells. Abstract : An effective p‐type doping strategy in Sb2 Se3 is proposed and a higher hole carrier density of 10 16 cm −3 is achieved for the first time, which shows the availability to optimize the performance of Sb2 Se3 ‐based solar cells. The defect physics that is decisive for the photovoltaic properties is revealed, providing guidance for further studies on doping in Sb2 Se3 .