The research progress of rare earth agricultural light conversion film

Abstract

The light-converting agricultural film is a new high-end functional film that can convert ultraviolet light and yellow-green light, which is harmful or useless to plant photosynthesis, into red-orange light or blue-violet light required for photosynthesis. The potential advantages of light-converting agricultural film in efficiently utilizing solar energy and improving crop yield have attracted more and more attention from researchers and agricultural enterprises.The light-converting function is realized by adding a light-converting agent to the agricultural film. Therefore, the preparation of light-converting agents with excellent performance is the core of the development and utilization of light-converting agricultural films. The paper firstly summarizes the key research and development in the field of agricultural light-converting films in china. Then this paper summarizes the classification of light-converting agents, research progress, and preparation methods. Finally, this paper predicts the future development trend of light-converting agricultural films, in order to provide a reference for the research and development of stable and efficient light-converting agricultural films.

Keywords: Light-converting agent; Light-converting agricultural film; Light-converting masterbatch; Rare earth.

Fig. 1

The schematic diagram of the light conversion process of the light-converting agricultural film.

Fig. 2

Different parameters of Chinese flowering cabbages obtained under the two films: (a) Biomass, (b) Leaves number, (c) Weight, (d) Photosynthetic pigment content, (e) Soluble protein content and the polyphenol content, (f) Soluble sugar content [24].

Fig. 3

The absorption spectrum of chlorophyll in plants [6].

Fig. 4

The schematic diagram of intramolecular energy transfer process in rare earth complexes [29].

Fig. 5

CIE 1931 chromaticity diagram for SrAl₂O₄:Eu²⁺,Dy³⁺and SrAl₂O₄:Eu²⁺,Dy³⁺/light conversion agent (a) and luminescent photograph of SrAl₂O₄:Eu²⁺,Dy³⁺/light conversion agent (b) [36].

Fig. 6

Schematic diagram of the formation of core-shell structured CaS:Eu²⁺@CaZnOS:Mn²⁺ (a) and Comparison of the integrate PLE and PL spectra of CaS:Eu, CaS:Eu@CaZnOS, and CaS:Eu@CaZnOS:0.5%Mn (b) [40].

Fig. 7

Powder phosphors of CaS:Eu²⁺ (A), CaS:Eu²⁺,CaF₂ (B), CaS:Eu²⁺,CaBr₂ (C), and CaS:Eu²⁺,CaBr₂,CaF₂ (D). (a) Comparison of thebody colors without (A–D) and with (A′− D′) moisture treatment for 180 days; (b) Photographs under daylight and UV-lamp excitation (the insets) after immersion for 10 min, 15 days, 30 days, and 60 days; (c) Variations of the emission intensities over time upon excitation by 525 nm; (d) PLE spectra (λ_em = 650 nm) [41]. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)