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In Cu2ZnSnS4 (CZTS) solar cells, it is crucial to suppress the generation of and remove the SnS2 secondary phase to improve the solar cell characteristics, as the SnS2 secondary phase affects the barrier for carrier collection and diode characteristics of the device. In this study, the nano-metallic precursor was modified to effectively suppress the generation of the SnS2 secondary phase on the surface and simultaneously improve the uniformity and quality of the thin film. The CZTS bifacial solar cells prepared via the proposed method exhibited significantly improved junction-rectifying characteristics, as the efficiency was improved to 1.59%. The proposed method to figurremove SnS2 is effective, simple, and environmentally friendly. [ABSTRACT FROM AUTHOR]

Summary: The Cu2ZnSnSe4 (CZTSe) absorber layer is typically prepared by post‐selenization with a metal precursor. In the process of selenization, the loss of SnSex is a common phenomenon, resulting in both an atomic‐ ratio change and double‐layer distribution of the absorber layer. This change affects the film properties. Additionally, excessive deviation from stoichiometry causes the formation of secondary‐phase compounds. Moreover, the double‐layer distribution reduces the carrier transport between the Mo back electrode and the CZTSe absorber film, inhibiting the effectiveness of the CZTSe solar cell. To address these problems, this study used CuxSe and ZnxSn1−x targets as the sputtering target materials to reduce the loss of SnSex during the selenization of precursor films. In addition, the effect of heating rate on the atomic ratio of the absorber layer was explored by adjusting the heating rate, which is one of the selenization parameters. The results showed that faster heating rates reduced the loss of SnSex, adjusted the Zn/Sn ratio in the absorber layer, and decreased ZnSe‐related defects. In this way, the double‐layer distribution was improved, air holes were reduced, and crystal structure characteristics of the films were enhanced. Photoluminescence (PL) spectroscopy showed that the signal of the ZnSe‐related defect decreased, and the band tail effect became insignificant. The CZTSe absorber layer fabricated under different heating rates is used to prepare the CZTSe solar cell with a photoelectric conversion efficiency ranging from 0.51% to 5.6%. [ABSTRACT FROM AUTHOR]

Summary: In this study, a flexible polydimethylsiloxane (PDMS) ARL with embedded ZnO‐NRs was fabricated on the surfaces of Cu(In,Ga)Se2 (CIGS) solar cells using the chemical solution method. Under the conditions of an AM1.5G solar spectrum, the application of the PDMS ARL of embedded ZnO‐NRs on the surface of a CIGS solar cell can effectively increase the conversion efficiency of the solar cell from 7.23% to 7.79%. In addition, broadband and omnidirectional light harvesting are important as the sun moves over time; therefore, omnidirectional anti‐reflection applications of various ARLs on CIGS photovoltaic cells were also studied. [ABSTRACT FROM AUTHOR]

In this study, the effect of the Cu concentration on the characteristics of the Cu2ZnSnSe4 (CZTSe) absorber layers and solar cells was systematically analyzed by postselenization of the evaporated precursor deposits. The results demonstrated that an increase in the copper concentration of the precursor linearly increased the Cu content in the final CZTSe thin‐film formation. This significantly increased the particle size and improved the re‐evaporation loss of the SnSe, thus improving the solar cell characteristics. However, a further increase in the Cu concentration reduced the quality of the absorber layer and formed either CuxSe or CTSe secondary phases, which was detrimental to the solar cell characteristics. Here, we introduce a sputtered CdS buffer layer for the CZTSe solar cells. These findings offer new research directions for solving the persistent challenges in the chemical bath deposition (CBD) of the CdS in the CZTSe solar cells. [ABSTRACT FROM AUTHOR]