Enhancement in the Efficiency of Sb2Se3 Thin‐Film Solar Cells by Increasing Carrier Concertation and Inducing Columnar Growth of the Grains

Abstract

Antimony selenide (Sb2Se3) thin films are attractive light‐absorbing materials for low‐cost and highly efficient thin‐film solar cells. Optimizing columnar growth of the grains and the proper hole concentration will be very helpful for improving the efficiency of Sb2Se3 thin‐film solar cells. In this paper, a monoatomic layer of Al2O3 prepared by the atomic layer deposition (ALD) method is used to increase the hole concentration of the Sb2Se3 film. The increase in the hole concentration is mainly due to the suppression of n‐type defects, such as Vse, or the increase in p‐type defects, such as Vsb. In addition, a simple and environmentally friendly oxygen plasma method is used to modify the CdS film to induce ordered columnar growth of the Sb2Se3 film deposited by the rapid thermal evaporation (RTE) method. Finally, an oxygen plasma treatment on CdS and a monoatomic Al2O3 layer covering the Sb2Se3 was combined to fabricate a solar cell with a new structure, FTO/CdS/P‐Sb2Se3/P+‐Sb2Se3/Al2O3/Au, and its efficiency was increased from 2.48% to 6.7%. These simple, nontoxic, and industrially applicable methods provide potential avenues for preparing low‐cost and highly efficient solar cells.