Enhancing the performance of multi-crystalline silicon photovoltaic module by encapsulating high efficient Eu3+ complex into its pre-existing EVA layer

Abstract Luminescent down shifting (LDS) technique is one effective way to improve the poor response of multi-crystalline silicon (mc-Si) photovoltaic (PV) modules at short wavelength less than 400 nm. Eu 3+ complexes are effective LDS species for PV modules due to their large stokes’ shift and high luminescent quantum efficiency (LQE). Although Eu 3+ complexes have been utilized in PV modules as LDS species widely, they have not been encapsulated into the pre-existing poly-ethylene vinyl acetate (EVA) layer of modules between glass and solar cell by now. The aim of our work is to enhance the performance of mc-Si PV modules by encapsulating high efficient Eu 3+ complexes into their pre-existing EVA layers which would not modify the well-established manufacturing process for PV modules. In this work, two Eu 3+ complexes with different absorption spectrum were encapsulated into the commercial EVA layer by soaking method for the first time and used in the encapsulation of mc-Si PV modules. Hereinto, Eu(TTA) 3 (TPPO) 2 (TTA = 2-thenoyltrifluoroacetonate, TPPO = triphenylphosphine oxide) (EuTT) with absorption spectrum less than 400 nm and high LQE (0.73) improves the external quantum efficiency of mc-Si PV module from 0.05 to 0.20, which produces a 0.42% increases in its power conversion efficiency. In addition, it is found that the enhancement brought by Eu(TTA) 3 (TPPO) 2 can reduce cost of power generated by mc-Si devices from US$1/ W p to US$0.98/ W p according to the calculation. Therefore, Eu(TTA) 3 (TPPO) 2 as LDS species with high LQE and low cost is promising for enhancing the performance of mc-Si PV modules in practical application.