Exploring the Effect of Selenidation Time on the Ni-Doped Cu2ZnSn(S,Se)4 Solar Cell

Abstract

The Cu2Ni0.05Zn0.95Sn(S,Se)4 (CNZTSSe) films were synthesized by sol-gel combined with selenidation treatment. To further enhance the crystal quality of the film, the selenidation conditions were optimized, and the effects of selenidation time on the properties of the CNZTSSe films and devices were systematically studied. The results show that the crystallinity of the films increased remarkably with the increase of selenidation time. Under the optimum selenidation time of 15 min, smooth and dense films were obtained. Through the analysis of EDS results, it is found that Se occupies more S positions with the increase of selenidation time, which decreases the band gap of the film from 1.14 eV to 1.0 eV. In addition, the formation of Zn-related defects is effectively suppressed by Ni doping to enhance the open circuit voltage (Voc) of the CNZTSSe solar cells. When the selenidation time is 15 min, the CNZTSSe film has the highest carrier concentration of 1.68 × 1016 cm−3, and the best efficiency of the device prepared based on the film as the absorption layer is 5.0%, and the Voc is 337 mV.

Designing Graded Band Gap Active Layer Cu2HgSn(S1–xSex)4 over Complex Tandem Structure for Efficient Photovoltaic Cells with Efficiency >20%

“…Notably, CIGS and CZTSSe-based solar cells are already materialized with band gap grading via introducing different ion concentrations due to different diffusion rates. − However, CZTSSe-based graded absorber with 12.25% power conversion efficiency is reported yet, which is still far below the single junction-based SQL of ∼33% . One of the possible reasons is the inhabiting Cu Zn disorder which always leads to recombination in the device.…”

Ultrafast and broadband photodetection based on selenized AgSbS2 thin films prepared by spray pyrolysis deposition and modified with indium nitrate

“…Upon conducting the aforementioned measurements, we deduce that Se diffusion was constrained by the grain boundaries, limiting the selenidation process primarily to the film's surface and the grain interfaces, particularly for shorter selenidation periods. 40 The addition of indium nitrate played a crucial role in refining the grain structure and creating a more loosely packed film, thus facilitating Se transport from the surface to the body of the film and generating a vertical gradient of Se distribution.…”