Application of downshifting and antireflection stacked layers synthesized using a wet chemistry method with broad UV excitation for silicon heterojunction solar cells

Abstract

Silicon heterojunction (SHJ) solar cells have enormous application prospects due to their high efficiency and small carbon footprint. However, during long-term use, the i-a-Si passivation layer of heterojunction (SHJ) solar cells tends to be destroyed by ultraviolet radiation, causing performance degradation. To eliminate this impact, downshifting (DS) materials of YVO₄:Eu³⁺,Bi³⁺ on the glass surface absorb ultraviolet light and convert it to wavelengths with a higher spectral response of SHJ solar cells. Furthermore, adding anti-reflection (AR) layers on the DS layer's surface will help maintain high transmittance and weather resistance. YVO₄:Eu³⁺,Bi³⁺ is prepared by using a wet chemical method, with no need for additional manufacturing of phosphors. The DS layer achieves uniform luminescence and expands the excitation spectrum. The average transmittance of glass coated with downshifting and anti-reflection (DSAR) is 96.80%, higher than that of glass with AR only. After high temperature and high humidity tests, the average transmittance of DSAR glass and the short-circuit current density of the module decreased by 1.44% and 0.59 mA cm⁻², much lower than that of AR coating (decreased) samples, which decreased by 2.53% and 1.43 mA cm⁻². After the UV test, the luminous intensity of the DSAR layer is much higher than that of the DS layer. Therefore, the DSAR layer could offer an easy industrialization approach to improve the outdoor reliability of SHJ solar cells.