Effect of low grain boundary crystallization Cu_2ZnSnS_xSe_(4_x) counter electrode on the performance of dye-sensitized solar cells

摘要

The high surface area of porous Cu2ZnSnSxSe4_x (CZTSSe) counter electrodes (CEs) was commonly used for dyesensitized solar cells (DSCs), because it can retard electron transport processes and form high quality crystallized film. Herein, we introduced a facile method to prepare CZTSSe film with bulk large-grained crystal by vacuum fast processing (VFP), which beneficial to form oriented crystalline film and reduce grain the film boundaries. Thus, performances of the DSCs devices showed an outstanding PCE of 8.3% with Voc, Jsc and fill factor of 0.729 V, 16.9 mA.cm_ 2, and 67.4%, respectively. With conducting spectral characterization and electrochemical techniques, it was found that the accelerating charge transfer speed and superior electrocatalytic activities contribute the majority part to DSCs photovoltaic performances. Furthermore, under AM1.5 illumination at 45 degrees C, the DSCs devices showed good stability and retained over 94% of its initial performance for 1000 h light soaking, indicating of their general applicability in fabricating high-performance DSCs.